Foto personale

Pagina personale di Olindo CORRADINI

Dipartimento di Scienze Fisiche, Informatiche e Matematiche
Dipartimento di Scienze Fisiche, Informatiche e Matematiche sede ex-Fisica

Ahmad, Aftab; Ahmadiniaz, Naser; Corradini, Olindo; Kim, Sang Pyo; Schubert, Christian ( 2017 ) - Master formulas for the dressed scalar propagator in a constant field - NUCLEAR PHYSICS. B - n. volume 919 - pp. da 9 a 24 ISSN: 0550-3213 [Articolo in rivista (262) - Articolo su rivista]
Abstract

The worldline formalism has previously been used for deriving compact master formulas for the one-loop N-photon amplitudes in both scalar and spinor QED, and in the vacuum as well as in a constant external field. For scalar QED, there is also an analogous master formula for the propagator dressed with N photons in the vacuum. Here, we extend this master formula to include a constant field. The two-photon case is worked out explicitly, yielding an integral representation for the Compton scattering cross section in the field suitable for numerical integration in the full range of electric and magnetic field strengths.

Bastianelli, Fiorenzo; Corradini, Olindo ( 2017 ) - On the simplified path integral on spheres - THE EUROPEAN PHYSICAL JOURNAL. C, PARTICLES AND FIELDS - n. volume 77 - pp. da 1 a 12 ISSN: 1434-6044 [Articolo in rivista (262) - Articolo su rivista]
Abstract

We have recently studied a simplified version of the path integral for a particle on a sphere, and more generally on maximally symmetric spaces, and proved that Riemann normal coordinates allow the use of a quadratic kinetic term in the particle action. The emerging linear sigma model contains a scalar effective potential that reproduces the effects of the curvature. We present here further details of the construction, and extend its perturbative evaluation to orders high enough to read off the type-A trace anomalies of a conformal scalar in dimensions d= 14 and d= 16.

Ahmadiniaz, Naser; Bastianelli, Fiorenzo; Corradini, Olindo; Edwards, James P; Schubert, Christian ( 2017 ) - One-particle reducible contribution to the one-loop spinor propagator in a constant field - NUCLEAR PHYSICS. B - n. volume 924 - pp. da 377 a 386 ISSN: 0550-3213 [Articolo in rivista (262) - Articolo su rivista]
Abstract

Extending work by Gies and Karbstein on the Euler–Heisenberg Lagrangian, it has recently been shown that the one-loop propagator of a charged scalar particle in a constant electromagnetic field has a one-particle reducible contribution in addition to the well-studied irreducible one. Here we further generalize this result to the spinor case, and find the same relation between the reducible term, the tree-level propagator and the one-loop Euler–Heisenberg Lagrangian as in the scalar case. Our demonstration uses a novel worldline path integral representation of the photon-dressed spinor propagator in a constant electromagnetic field background.

Bastianelli, Fiorenzo; Corradini, Olindo; Vassura, Edoardo ( 2017 ) - Quantum mechanical path integrals in curved spaces and the type-A trace anomaly - JOURNAL OF HIGH ENERGY PHYSICS - n. volume 2017 - pp. da 0 a 18 ISSN: 1029-8479 [Articolo in rivista (262) - Articolo su rivista]
Abstract

Path integrals for particles in curved spaces can be used to compute trace anomalies in quantum field theories, and more generally to study properties of quantum fields coupled to gravity in first quantization. While their construction in arbitrary coordi- nates is well understood, and known to require the use of a regularization scheme, in this article we take up an old proposal of constructing the path integral by using Riemann nor- mal coordinates. The method assumes that curvature effects are taken care of by a scalar effective potential, so that the particle lagrangian is reduced to that of a linear sigma model interacting with the effective potential. After fixing the correct effective potential, we test the construction on spaces of maximal symmetry and use it to compute heat kernel coef- ficients and type-A trace anomalies for a scalar field in arbitrary dimensions up to d = 12. The results agree with expected ones, which are reproduced with great efficiency and ex- tended to higher orders. We prove explicitly the validity of the simplified path integral on maximally symmetric spaces. This simplified path integral might be of further use in world- line applications, though its application on spaces of arbitrary geometry remains unclear.

Ahmadiniaz, Naser; Bastianelli, Fiorenzo; Corradini, Olindo ( 2016 ) - Dressed scalar propagator in a non-Abelian background from the worldline formalism - PHYSICAL REVIEW. D - n. volume 93 (2016) 025025 - pp. da 1 a 13 ISSN: 2470-0029 [Articolo in rivista (262) - Articolo su rivista]
Abstract

We study the propagator of a colored scalar particle in the background of a non-abelian gauge field using the worldline formalism. It is obtained by considering the open worldline of a scalar particle with extra degrees of freedom needed to take into account the color charge of the particle, which we choose to be in the fundamental representation of the gauge group. Specializing the external gauge field to be given by a sum of plane waves, i.e. a sum of external gluons, we produce a master formula for the scalar propagator with an arbitrary number of gluons directly attached to the scalar line, akin to similar formulas derived in the literature for the case of the scalar particle performing a loop. Our worldline description produces at the same time the situation in which the particle has a color charge given by an arbitrarily chosen symmetric or antisymmetric tensor product of the fundamental.

Ahmadiniaz, Naser; Corradini, Olindo; Davila, Jose Manuel; Schubert, Christian ( 2016 ) - Gravitational Compton Scattering from the Worldline Formalism ( 12th International Symposium on Cosmology and Particle Astrophysics (CosPA 2015) - Daejeon, Republic of Korea - 12-16 Oct 2015) ( - Proceedings, 12th International Symposium on Cosmology and Particle Astrophysics (CosPA 2015) : Daejeon, Republic of Korea, October 12-16, 2015 ) (World Scientific SGP ) - n. volume 43 (2016) 1660201 - pp. da 1 a 9 [Contributo in Atti di convegno (273) - Relazione in Atti di Convegno]
Abstract

We report on an ongoing study of photon amplitudes, graviton amplitudes and mixed photon-graviton amplitudes at tree-level using the worldline formalism. We explicitly recalculate the amplitude with one photon and one graviton coupled to a scalar propagator, relevant for graviton photoproduction. We comment on the factorization properties of this amplitude, and outline a generalization to similar processes involving more gravitons.

Corradini, Olindo; Edwards, James P. ( 2016 ) - Mixed symmetry tensors in the worldline formalism - JOURNAL OF HIGH ENERGY PHYSICS - n. volume 5 (2016) 056 - pp. da 0 a 29 ISSN: 1029-8479 [Articolo in rivista (262) - Articolo su rivista]
Abstract

We consider the first quantised approach to quantum field theory coupled to a non-Abelian gauge field. Representing the colour degrees of freedom with a single family of auxiliary variables the matter field transforms in a reducible representation of the gauge group which — by adding a suitable Chern-Simons term to the particle action — can be projected onto a chosen fully (anti-)symmetric representation. By considering F families of auxiliary variables, we describe how to extend the model to arbitrary tensor products of F reducible representations, which realises a U(F) “flavour” symmetry on the world- line particle model. Gauging this symmetry allows the introduction of constraints on the Hilbert space of the colour fields which can be used to project onto an arbitrary irreducible representation, specified by a certain Young tableau. In particular the occupation num- bers of the wavefunction — i.e. the lengths of the columns (rows) of the Young tableau — are fixed through the introduction of Chern-Simons terms. We verify this projection by calculating the number of colour degrees of freedom associated to the matter field. We sug- gest that, using the worldline approach to quantum field theory, this mechanism will allow the calculation of one-loop scattering amplitudes with the virtual particle in an arbitrary representation of the gauge group.

Edwards, James P; Corradini, Olindo ( 2016 ) - Mixed symmetry Wilson-loop interactions in the worldline formalism - JOURNAL OF HIGH ENERGY PHYSICS - n. volume 2016 - pp. da 0 a 43 ISSN: 1126-6708 [Articolo in rivista (262) - Articolo su rivista]
Abstract

Using the worldline formalism of the Dirac field with a non-Abelian gauge symmetry we show how to describe the matter field transforming in an arbitrary representation of the gauge group. Colour degrees of freedom are carried on the worldline by auxiliary fields, responsible for providing path ordering and the Wilson-loop coupling. The Hilbert space of these fields is reducible but we make use of recent work in order to project onto a single, arbitrary, irreducible representation. By functionally quantising the resulting theory we show that this procedure correctly generates the Wilson-loop interaction between the gauge field and the matter field taken to transform in a chosen representation. This work has direct application to physical observables such as scattering amplitudes in the presence of such a matter multiplet and lifts the restriction on the type of matter that has previously featured in worldline calculations.

Vaquera-Araujo, Carlos A.; Corradini, Olindo ( 2015 ) - Localization of abelian gauge fields on thick branes - THE EUROPEAN PHYSICAL JOURNAL. C, PARTICLES AND FIELDS - n. volume 75 - pp. da 1 a 9 ISSN: 1434-6044 [Articolo in rivista (262) - Articolo su rivista]
Abstract

In this work, we explore a mechanism for abelian gauge field localization on thick branes based on a five-dimensional Stueckelberg-like action. A normalizable zero mode is found through the identification of a suitable coupling function between the brane and the gauge field. The same mechanism is studied for the localization of the abelian Kalb--Ramond field.

Naser, Ahmadiniaz; Olindo, Corradini; D'Ascanio, Daniela; Estrada-Jimenez, Sendic; Pisani, Pablo ( 2015 ) - Noncommutative U(1) gauge theory from a worldline perspective - JOURNAL OF HIGH ENERGY PHYSICS - n. volume 2015 - pp. da 1 a 28 ISSN: 1029-8479 [Articolo in rivista (262) - Articolo su rivista]
Abstract

We study pure noncommutative U(1) gauge theory representing its one-loop effective action in terms of a phase space worldline path integral. We write the quadratic action using the background field method to keep explicit gauge invariance, and then employ the worldline formalism to write the one-loop effective action, singling out UV-divergent parts and finite (planar and non-planar) parts, and study renormalization properties of the theory. This amounts to employ worldline Feynman rules for the phase space path integral, that nicely incorporate the Fadeev-Popov ghost contribution and efficiently separate planar and non-planar contributions. We also show that the effective action calculation is independent of the choice of the worldline Green's function, that corresponds to a particular way of factoring out a particle zero-mode. This allows to employ homogeneous string-inspired Feynman rules that greatly simplify the computation.

Bonezzi, R.; Corradini, O.; Latini, E.; Waldron, A. ( 2015 ) - Quantum gravity and causal structures: Second quantization of conformal Dirac algebras - PHYSICAL REVIEW D, PARTICLES, FIELDS, GRAVITATION, AND COSMOLOGY - n. volume 91 - pp. da 1 a 4 ISSN: 1550-7998 [Articolo in rivista (262) - Articolo su rivista]
Abstract

It is postulated that quantum gravity is a sum over causal structures coupled to matter via scale evolution. Quantized causal structures can be described by studying simple matrix models where matrices are replaced by an algebra of quantum mechanical observables. In particular, previous studies constructed quantum gravity models by quantizing the moduli of Laplace, weight, and defining-function operators on Fefferman–Graham ambient spaces. The algebra of these operators underlies conformal geometries. We extend those results to include fermions by taking an osp(1j2) “Dirac square root” of these algebras. The theory is a simple, Grassmann, two-matrix model. Its quantum action is a Chern–Simons theory whose differential is a first-quantized, quantum mechanical Becchi-Rouet-Stora-Tyutin operator. The theory is a basic ingredient for building fundamental theories of physical observables.

Grandi, F.; Manghi, F.; Corradini, O.; Bertoni, C. M.; Bonini, A. ( 2015 ) - Topological invariants in interacting quantum spin Hall: a cluster perturbation theory approach - NEW JOURNAL OF PHYSICS - n. volume 17 - pp. da 1 a 8 ISSN: 1367-2630 [Articolo in rivista (262) - Articolo su rivista]
Abstract

Using cluster perturbation theory we calculate Greenʼs functions, quasi-particle energies and topological invariants for interacting electrons on a 2Dhoneycomb lattice, with intrinsic spin–orbit coupling and on-site e–e interaction. This allows us to define the parameter range (HubbardUversus spin– orbit coupling) where the 2D system behaves as a trivial insulator or quantum spin Hall insulator. This behavior is confirmed by the existence of gapless quasi-particle states in honeycomb ribbons.Wehave discussed the importance of the cluster symmetry and the effects of the lack of full translation symmetry typical of CPT and of most quantum cluster approaches. Comments on the limits of applicability of the method are also provided.

Grandi, F.; Manghi, F.; Corradini, O.; Bertoni, C. M. ( 2015 ) - Topological properties of the bond-modulated honeycomb lattice - PHYSICAL REVIEW. B, CONDENSED MATTER AND MATERIALS PHYSICS - n. volume 91 - pp. da 1 a 7 ISSN: 1098-0121 [Articolo in rivista (262) - Articolo su rivista]
Abstract

We study the combined effects of lattice deformation, e−e interaction, and spin-orbit coupling in a two-dimensional (2D) honeycomb lattice. We adopt different kinds of hopping modulation—generalized dimerization and a Kekulé distortion—and calculate topological invariants for the noninteracting system and for the interacting system. We identify the parameter range (Hubbard U, hopping modulation, spin-orbit coupling) where the 2D system behaves as a trivial insulator or quantum spin Hall insulator.

Bonezzi, R.; Corradini, O.; Waldron, A. ( 2014 ) - Is quantum gravity a Chern-Simons theory? - PHYSICAL REVIEW D, PARTICLES, FIELDS, GRAVITATION, AND COSMOLOGY - n. volume 90 (2014) 8, 084018 - pp. da 1 a 11 ISSN: 1550-7998 [Articolo in rivista (262) - Articolo su rivista]
Abstract

We propose a model of quantum gravity in arbitrary dimensions defined in terms of the Batalin Vilkovisky (BV) quantization of a supersymmetric, infinite dimensional matrix model. This gives an Alexandrov-Kontsevich-Schwarz-Zaboronsky (AKSZ)-type Chern-Simons theory with gauge algebra the space of observables of a quantum mechanical Hilbert space H. The model is motivated by previous attempts to formulate gravity in terms of noncommutative, phase space, field theories as well as the Fefferman-Graham (FG) curved analog of Dirac spaces for conformally invariant wave equations. The field equations are flat connection conditions amounting to zero curvature and parallel conditions on operators acting on H. This matrix-type model may give a better defined setting for a quantum gravity path integral. We demonstrate that its underlying physics is a summation over Hamiltonians labeled by a conformal class of metrics and thus a sum over causal structures. This gives in turn a model summing over fluctuating metrics plus a tower of additional modes—we speculate that these could yield improved UV behavior.

Bastianelli, Fiorenzo; Bonezzi, Roberto; Corradini, Olindo; Latini, Emanuele ( 2014 ) - Massive and massless higher spinning particles in odd dimensions - JOURNAL OF HIGH ENERGY PHYSICS - n. volume 09 (2014) 158 - pp. da 0 a 27 ISSN: 1029-8479 [Articolo in rivista (262) - Articolo su rivista]
Abstract

Abstract: We study actions for massive bosonic particles of higher spins by dimensionally reducing an action for massless particles. For the latter we take a model with a SO(N) extended local supersymmetry on the worldline, that is known to describe massless (confor- mal) particles of higher spins in flat spacetimes of even dimensions. Dimensional reduction produces an action for massive spinning particles in odd dimensions. The field equations that emerge in a quantization `a la Dirac are shown to be equivalent to the Fierz-Pauli ones. The massless limit generates a multiplet of massless states with higher spins, whose first quantized field equations have a geometric form with fields belonging to various types of Young tableaux. These geometric equations can be partially integrated to show their equiv- alence with the standard Fronsdal-Labastida equations. We covariantize our model to check whether an extension to curved spacetimes can be achieved. Restricting to (A)dS spaces, we find that the worldline gauge algebra becomes nonlinear, but remains first class. This guar- antees consistency on such backgrounds. A light cone analysis confirms the presence of the expected propagating degrees of freedom. A covariant analysis is worked out explicitly for the massive case, which is seen to give rise to the Fierz-Pauli equations extended to (A)dS spaces. It is worth noting that in D = 3 the massless limit of our model with N → ∞ has the same field content of the Vasiliev’s theory that accommodates each spin exactly once.

Herrera-Aguilar, A.; Nucamendi, U.; Santos, E.; Corradini, O.; Alvarez, C. ( 2013 ) - On the galactic rotation curves problem within an axisymmetric approach - MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY - n. volume 432 - pp. da 301 a 306 ISSN: 0035-8711 [Articolo in rivista (262) - Articolo su rivista]
Abstract

In U. Nucamendi et al. Phys. Rev. D63 (2001) 125016 and K. Lake, Phys. Rev. Lett. 92 (2004) 051101 it has been shown that galactic potentials can be kinematically linked to the observed red/blue shifts of the corresponding galactic rotation curves under a minimal set of assumptions: the emitted photons come from stable timelike circular geodesic orbits of stars in a static spherically symmetric gravitational field, and propagate to us along null geodesics. It is remarkable that this relation can be established without appealing at all to a concrete theory of gravitational interaction. Here we generalize this kinematical spherically symmetric approach to the galactic rotation curves problem to the stationary axisymmetric realm since this is precisely the symmetry that spiral galaxies possess. Thus, by making use of the most general stationary axisymmetric metric, we also consider stable circular orbits of stars that emit signals which travel to a distant observer along null geodesics and express the galactic red/blue shifts in terms of three arbitrary metric functions, clarifying the contribution of the rotation as well as the dragging of the gravitational field. This stationary axisymmetric approach distinguishes between red and blue shifts emitted by circularly orbiting receding and approaching stars, respectively, even when they are considered with respect to the center of a spiral galaxy, indicating the need of precise measurements in order to confront predictions with observations. We also point out the difficulties one encounters in the attempt of determining the metric functions from observations and list some possible strategies to overcome them.

Bastianelli, Fiorenzo; Bonezzi, Roberto; Corradini, Olindo; Latini, Emanuele ( 2013 ) - Particles with non abelian charges - JOURNAL OF HIGH ENERGY PHYSICS - n. volume 1310 (2013) 098 - pp. da 0 a 12 ISSN: 1029-8479 [Articolo in rivista (262) - Articolo su rivista]
Abstract

Efficient methods for describing non abelian charges in worldline approaches to QFT are useful to simplify calculations and address structural properties, as for example color/kinematics relations. Here we analyze in detail a method for treating arbitrary non abelian charges. We use Grassmann variables to take into account color degrees of freedom, which however are known to produce reducible representations of the color group. Then we couple them to a U(1) gauge field defined on the worldline, together with a Chern-Simons term, to achieve projection on an irreducible representation. Upon gauge fixing there remains a modulus, an angle parametrizing the U(1) Wilson loop, whose dependence is taken into account exactly in the propagator of the Grassmann variables. We test the method in simple examples, the scalar and spin 1/2 contribution to the gluon self energy, and suggest that it might simplify the analysis of more involved amplitudes.

Ahmadiniaz, N.; Bastianelli, F.; Corradini, O.; Dávila, José M.; Schubert, C. ( 2013 ) - Photon-graviton amplitudes ( IX MEXICAN SCHOOL ON GRAVITATION AND MATHEMATICAL PHYSICS: COSMOLOGY FOR THE XXIST CENTURY - Puerto Vallarta (Messico) - 3-7 dicembre 2012) ( - AIP Conference Proceedings ) - AIP CONFERENCE PROCEEDINGS - pp. da 221 a 226 ISSN: 0094-243X [Contributo in Atti di convegno (273) - Relazione in Atti di Convegno]
Abstract

We report on an ongoing study of the one-loop photon-graviton amplitudes, using both effective action and worldline techniques. The emphasis is on Kawai-Lewellen-Tye-like relations.

Bastianelli, Fiorenzo; Bonezzi, Roberto; Corradini, Olindo; Latini, Emanuele ( 2012 ) - Effective action for higher spin fields on (A)dS backgrounds - JOURNAL OF HIGH ENERGY PHYSICS - n. volume 1212 (2012) 113 - pp. da 0 a 26 ISSN: 1029-8479 [Articolo in rivista (262) - Articolo su rivista]
Abstract

We study the one loop effective action for a class of higher spin fields by using a first-quantized description. The latter is obtained by considering spinning particles, characterized by an extended local supersymmetry on the worldline, that can propagate consistently on conformally flat spaces. The gauge fixing procedure for calculating the worldline path integral on a loop is delicate, as the gauge algebra contains nontrivial structure functions. Restricting the analysis on (A)dS backgrounds simplifies the gauge fixing procedure, and allows us to produce a useful representation of the one loop effective action. In particular, we extract the first few heat kernel coefficients for arbitrary even spacetime dimension D and for spin S identified by a curvature tensor with the symmetries of a rectangular Young tableau of D/2 rows and [S] columns.

Bastianelli, F.; Corradini, O.; Dávila, J.M.; Schubert, C. ( 2012 ) - On the low-energy limit of one-loop photon–graviton amplitudes - PHYSICS LETTERS. SECTION B - n. volume B716 (2012) - pp. da 345 a 349 ISSN: 0370-2693 [Articolo in rivista (262) - Articolo su rivista]
Abstract

We present first results of a systematic study of the structure of the low energy limit of the one-loop photon-graviton amplitudes induced by massive scalars and spinors. Our main objective is the search of KLT-type relations where effectively two photons merge into a graviton. We find such a relation at the graviton-photon-photon level. We also derive the diffeomorphism Ward identity for the 1PI one graviton - N photon amplitudes.

Bonezzi, R; Corradini, O; Viñas, S A Franchino; Pisani, P A G ( 2012 ) - Worldline approach to noncommutative field theory - JOURNAL OF PHYSICS. A, MATHEMATICAL AND THEORETICAL - n. volume 45 (2012) 405401 - pp. da 1 a 15 ISSN: 1751-8113 [Articolo in rivista (262) - Articolo su rivista]
Abstract

The study of the heat-trace expansion in noncommutative field theory has shown the existence of Moyal nonlocal Seeley-DeWitt coefficients which are related to the UV/IR mixing and manifest, in some cases, the non-renormalizability of the theory. We show that these models can be studied in a worldline approach implemented in phase space and arrive to a master formula for the $n$-point contribution to the heat-trace expansion. This formulation could be useful in understanding some open problems in this area, as the heat-trace expansion for the noncommutative torus or the introduction of renormalizing terms in the action, as well as for generalizations to other nonlocal operators.

Alvarado, Carlos; Aranda, Alfredo; Corradini, Olindo; Rojas, Alma D.; Santos-Rodriguez, Eli ( 2012 ) - Z4flavor model in Randall-Sundrum model 1 - PHYSICAL REVIEW D, PARTICLES, FIELDS, GRAVITATION, AND COSMOLOGY - n. volume 86 (2012) 036010 - pp. da 1 a 12 ISSN: 1550-7998 [Articolo in rivista (262) - Articolo su rivista]
Abstract

Randall Sundrum models provide a possible explanation of (gauge-gravity) hierarchy, whereas discrete symmetry flavor groups yield a possible description of the texture of Standard Model fermion masses. We use both these ingredients to propose a five-dimensional extension of the Standard Model where the mass hierarchy of the four-dimensional effective field theory is obtained only using localizations parameters of order 1. We consider a bulk custodial gauge symmetry group together with an Abelian $Z_4$ group: the model turns out to yield a rather minimal extension of the SM as it only requires two brane Higgs fields to provide the desired Yukawa interactions and the required spontaneous symmetry breaking pattern. In fact, the presence of an extra-dimension allows the use of the Scherk-Schwarz mechanism to contribute to the breaking of the bulk custodial group down to the SM gauge symmetry. Moreover, no right-handed neutrinos are present and neutrino masses are generated radiatively with the help of a bulk charged scalar field that provides the Lepton-number violation. Using experimental inputs from the Global Neutrino Analysis and recent Daya Bay results, a numerical analysis is performed and allowed parameter regions are displayed.

Bastianelli, Fiorenzo; Bonezzi, Roberto; Corradini, Olindo; Latini, Emanuele ( 2011 ) - Extended SUSY quantum mechanics: transition amplitudes and path integrals - JOURNAL OF HIGH ENERGY PHYSICS - n. volume 1106 (2011) 023 - pp. da 0 a 26 ISSN: 1029-8479 [Articolo in rivista (262) - Articolo su rivista]
Abstract

Quantum mechanical models with extended supersymmetry find interesting applications in worldline approaches to relativistic field theories. In this paper we consider one-dimensional nonlinear sigma models with O(N) extended supersymmetry on the worldline, which are used in the study of higher spin fields on curved backgrounds. We calculate the transition amplitude for euclidean times (i.e. the heat kernel) in a perturbative expansion, using both canonical methods and path integrals. The latter are constructed using three different regularization schemes, and the corresponding counterterms that ensure scheme independence are explicitly identified.

Corradini, Olindo ( 2010 ) - Half-integer higher spin fields in (A)dS from spinning particle models - JOURNAL OF HIGH ENERGY PHYSICS - n. volume 1009 (2010) 113 - pp. da 0 a 19 ISSN: 1029-8479 [Articolo in rivista (262) - Articolo su rivista]
Abstract

We make use of O(2r+1) spinning particle models to construct linearized higher-spin curvatures in (A)dS spaces for fields of arbitrary half-integer spin propagating in a space of arbitrary (even) dimension: the field potentials, whose curvatures are computed with the present models, are spinor-tensors of mixed symmetry corresponding to Young tableaux with D/2 - 1 rows and r columns, thus reducing to totally symmetric spinor-tensors in four dimensions. The paper generalizes similar results obtained in the context of integer spins in (A)dS.

Corradini, Olindo ( 2010 ) - Smooth tensionful higher-codimensional brane worlds with bulk and brane form fields - JOURNAL OF HIGH ENERGY PHYSICS - n. volume 1001 (2010) 051 - pp. da 0 a 15 ISSN: 1029-8479 [Articolo in rivista (262) - Articolo su rivista]
Abstract

Completely regular tensionful codimension-n brane world solutions are discussed, where the core of the brane is chosen to be a thin codimension-(n-1) shell in an infinite volume flat bulk, and an Einstein-Hilbert term localized on the brane is included (Dvali-Gabadadze-Porrati models). In order to support such localized sources we enrich the vacuum structure of the brane by the inclusion of localized form fields. We find that phenomenological constraints on the size of the internal core seem to impose an upper bound to the brane tension. Finite transverse-volume smooth solutions are also discussed.

Bastianelli, Fiorenzo; Corradini, Olindo; Waldron, Andrew ( 2009 ) - Detours and paths: BRST complexes and worldline formalism - JOURNAL OF HIGH ENERGY PHYSICS - n. volume 0905 (2009) 017 - pp. da 0 a 32 ISSN: 1029-8479 [Articolo in rivista (262) - Articolo su rivista]
Abstract

We construct detour complexes from the BRST quantization of worldline diffeomorphism invariant systems. This yields a method to efficiently extract physical quantum field theories from particle models with first class constraint algebras. As an example, we show how to obtain the Maxwell detour complex by gauging N=2 supersymmetric quantum mechanics in curved space. Then we concentrate on first class algebras belonging to a class of recently introduced orthosymplectic quantum mechanical models and give generating functions for detour complexes describing higher spins of arbitrary symmetry types. The first quantized approach facilitates quantum calculations and we employ it to compute the number of physical degrees of freedom associated to the second quantized, field theoretical actions.

Corradini, O; Faccioli, P; Orland, H ( 2009 ) - Simulating stochastic dynamics using large time steps - PHYSICAL REVIEW E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS - n. volume 80 (2009) 061112 - pp. da 1 a 13 ISSN: 1539-3755 [Articolo in rivista (262) - Articolo su rivista]
Abstract

We present an approach to investigate the long-time stochastic dynamics of multidimensional classical systems, in contact with a heat bath. When the potential energy landscape is rugged, the kinetics displays a decoupling of short- and long-time scales and both molecular dynamics or Monte Carlo (MC) simulations are generally inefficient. Using a field theoretic approach, we perform analytically the average over the short-time stochastic fluctuations. This way, we obtain an effective theory, which generates the same long-time dynamics of the original theory, but has a lower time-resolution power. Such an approach is used to develop an improved version of the MC algorithm, which is particularly suitable to investigate the dynamics of rare conformational transitions. In the specific case of molecular systems at room temperature, we show that elementary integration time steps used to simulate the effective theory can be chosen a factor approximately 100 larger than those used in the original theory. Our results are illustrated and tested on a simple system, characterized by a rugged energy landscape.

Corradini, Olindo; Koyama, Kazuya; Tasinato, Gianmassimo ( 2008 ) - Induced gravity on intersecting brane worlds. II. Cosmology - PHYSICAL REVIEW D, PARTICLES, FIELDS, GRAVITATION, AND COSMOLOGY - n. volume D78 (2008) 124002 - pp. da 1 a 11 ISSN: 1550-7998 [Articolo in rivista (262) - Articolo su rivista]
Abstract

We explore cosmology of intersecting braneworlds with induced gravity on the branes. We find the cosmological equations that control the evolution of a moving codimension one brane and a codimension two brane that sits at the intersection. We study the Friedmann equation at the intersection, finding new contributions from the six dimensional bulk. These higher dimensional contributions allow us to find new examples of self-accelerating configurations for the codimension two brane at the intersection and we discuss their features.

Corradini, Olindo; Koyama, Kazuya; Tasinato, Gianmassimo ( 2008 ) - Induced gravity on intersecting brane worlds: Maximally symmetric solutions - PHYSICAL REVIEW D, PARTICLES, FIELDS, GRAVITATION, AND COSMOLOGY - n. volume D77 (2008) 084006 - pp. da 1 a 9 ISSN: 1550-7998 [Articolo in rivista (262) - Articolo su rivista]
Abstract

We explore models of intersecting brane-worlds with induced gravity terms on codimension one branes and on their intersection. Maximally symmetric solutions for the branes and the intersection are found. We find new self-accelerating solutions. In a 6d spacetime, the solutions realize the see-saw modification of gravity where the UV scale of the modification to 4d gravity is determined by 6d Planck scale given by $M_6 \sim 10^-3$eV and the IR scale of the modification is determined by $M_6^2/M_4 \sim H_0 \sim 10^-42$ GeV where $H_0$ is present-day Hubble scale. We find that it is increasingly difficult to construct phenomenologically viable models in higher-dimensional spacetime due to the necessity to have the lower value for the fundamental Planck scale to realize the late time acceleration. It is found that the system also admits self-tuning solutions where the tension at the intersection does not change the geometry of the intersection. The induced gravity terms can avoid the necessity to compactify the extra dimensions. Finally, we discuss the possibility to have ordinary matter at the intersection, without introducing any regularisation, using the induced gravity terms.

Bastianelli, Fiorenzo; Corradini, Olindo; Pisani, Pablo A G ( 2008 ) - Scalar field with Robin boundary conditions in the worldline formalism - JOURNAL OF PHYSICS. A, MATHEMATICAL AND THEORETICAL - n. volume A41 (2008) 164010 - pp. da 1 a 7 ISSN: 1751-8113 [Articolo in rivista (262) - Articolo su rivista]
Abstract

The worldline formalism has been widely used to compute physical quantities in quantum field theory. However, applications of this formalism to quantum fields in the presence of boundaries have been studied only recently. In this article we show how to compute in the worldline approach the heat kernel expansion for a scalar field with boundary conditions of Robin type. In order to describe how this mechanism works, we compute the contributions due to the boundary conditions to the coefficients A_1, A_3/2 and A_2 of the heat kernel expansion of a scalar field on the positive real line.

Bastianelli, Fiorenzo; Corradini, Olindo; Pisani, Pablo A.G; Schubert, Christian ( 2008 ) - Scalar heat kernel with boundary in the worldline formalism - JOURNAL OF HIGH ENERGY PHYSICS - n. volume 0810 (2008) 095 - pp. da 0 a 20 ISSN: 1029-8479 [Articolo in rivista (262) - Articolo su rivista]
Abstract

The worldline formalism has in recent years emerged as a powerful tool for the computation of effective actions and heat kernels. However, implementing nontrivial boundary conditions in this formalism has turned out to be a difficult problem. Recently, such a generalization was developed for the case of a scalar field on the half-space R_+ x R^D-1, based on an extension of the associated worldline path integral to the full R^D using image charges. We present here an improved version of this formalism which allows us to write down non-recursive master formulas for the n-point contribution to the heat kernel trace of a scalar field on the half-space with Dirichlet or Neumann boundary conditions. These master formulas are suitable to computerization. We demonstrate the efficiency of the formalism by a calculation of two new heat-kernel coefficients for the half-space, a_4 and a_9/2.

Bastianelli, Fiorenzo; Corradini, Olindo; Latini, Emanuele ( 2008 ) - Spinning particles and higher spin fields on (A)dS backgrounds - JOURNAL OF HIGH ENERGY PHYSICS - n. volume 0811 (2008) 054 - pp. da 0 a 32 ISSN: 1029-8479 [Articolo in rivista (262) - Articolo su rivista]
Abstract

Spinning particle models can be used to describe higher spin fields in first quantization. In this paper we discuss how spinning particles with gauged O(N) supersymmetries on the worldline can be consistently coupled to conformally flat spacetimes, both at the classical and at the quantum level. In particular, we consider canonical quantization on flat and on (A)dS backgrounds, and discuss in detail how the constraints due to the worldline gauge symmetries produce geometrical equations for higher spin fields, i.e. equations written in terms of generalized curvatures. On flat space the algebra of constraints is linear, and one can integrate part of the constraints by introducing gauge potentials. This way the equivalence of the geometrical formulation with the standard formulation in terms of gauge potentials is made manifest. On (A)dS backgrounds the algebra of constraints becomes quadratic, nevertheless one can use it to extend much of the previous analysis to this case. In particular, we derive general formulas for expressing the curvatures in terms of gauge potentials and discuss explicitly the cases of spin 2, 3 and 4.

Corradini, Olindo; Iglesias, Alberto ( 2008 ) - Trace anomaly inflation in brane-induced gravity - JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS - n. volume 0805 (2008) 012 - pp. da 0 a 14 ISSN: 1475-7516 [Articolo in rivista (262) - Articolo su rivista]
Abstract

In the present letter we find that Starobinsky's inflationary solution is also valid in the Dvali-Gabadadze-Porrati (DGP) model where a 3-brane is embedded in 5-dimensional Minkowski bulk. We show that such a solution is typically not supported by the Self-Accelerated branch of the model, giving therefore a natural selection of the conventional branch of solutions. In the absence of brane induced Einstein-Hilbert term the SA branch is always selected out. We then study the linearized modes around all such de Sitter brane solutions finding perturbative stability for a range of parameters of the brane QFT.

Fiorenzo, Bastianelli; Olindo, Corradini; Emanuele, Latini ( 2007 ) - Higher spin fields from a worldline perspective - JOURNAL OF HIGH ENERGY PHYSICS - n. volume 0702 (2007) 072 - pp. da 0 a 18 ISSN: 1029-8479 [Articolo in rivista (262) - Articolo su rivista]
Abstract

Higher spin fields in four dimensions, and more generally conformal fields in arbitrary dimensions, can be described by spinning particle models with a gauged SO(N) extended supergravity on the worldline. We consider here the one-loop quantization of these models by studying the corresponding partition function on the one-dimensional torus. After gauge fixing the supergravity multiplet, the partition function reduces to an integral over the corresponding moduli space which is computed using orthogonal polynomial techniques. We obtain a compact formula which gives the number of physical degrees of freedom for all N in all dimensions. As an aside we compute the physical degrees of freedom of the SO(4) = SU(2)xSU(2) model with only a SU(2) factor gauged, which has attracted some interest in the literature.

Bastianelli, Fiorenzo; Corradini, Olindo; Pisani, Pablo A. G ( 2007 ) - Worldline approach to quantum field theories on flat manifolds with boundaries - JOURNAL OF HIGH ENERGY PHYSICS - n. volume 0702 (2007) 059 - pp. da 0 a 17 ISSN: 1029-8479 [Articolo in rivista (262) - Articolo su rivista]
Abstract

We study a worldline approach to quantum field theories on flat manifolds with boundaries. We consider the concrete case of a scalar field propagating on R_+ x R^D-1 which leads us to study the associated heat kernel through a one dimensional (worldline) path integral. To calculate the latter we map it onto an auxiliary path integral on the full R^D using an image charge. The main technical difficulty lies in the fact that a smooth potential on R_+ x R^D-1 extends to a potential which generically fails to be smooth on R^D. This implies that standard perturbative methods fail and must be improved. We propose a method to deal with this situation. As a result we recover the known heat kernel coefficients on a flat manifold with geodesic boundary, and compute two additional ones, A_3 and A_7/2. The calculation becomes sensibly harder as the perturbative order increases, and we are able to identify the complete A_7/2 with the help of a suitable toy model. Our findings show that the worldline approach is viable on manifolds with boundaries. Certainly, it would be desirable to improve our method of implementing the worldline approach to further simplify the perturbative calculations that arise in the presence of non-smooth potentials.

Corradini, Olindo; Rinaldi, Massimiliano ( 2006 ) - Self-T-dual brane cosmology and the cosmological constant problem - JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS - n. volume 0601 (2006) 020 - pp. da 0 a 15 ISSN: 1475-7516 [Articolo in rivista (262) - Articolo su rivista]
Abstract

We consider a codimension-one brane embedded in a gravity-dilaton bulk action, whose symmetries are compatible with T-duality along the space-like directions parallel to the brane, and the bulk time-like direction. The equations of motions in the string frame allow for a smooth background obtained by the union of two symmetric patches of AdS space. The Poincar\'e invariance of the solution appears to hold independently of the value of the brane vacuum energy, through a self-tuning property of the dilaton ground state. Moreover, the effective cosmology displays a bounce, at which the scale factor does not shrink to zero. Finally, by exploiting the T-duality symmetry, we show how to construct an ever-expanding Universe, along the lines of the Pre-Big Bang scenario.

Corradini, Olindo ( 2005 ) - 4D gravity on a brane from bulk higher-curvature terms - MODERN PHYSICS LETTERS A - n. volume A20 (2005) - pp. da 2775 a 2783 ISSN: 0217-7323 [Articolo in rivista (262) - Articolo su rivista]
Abstract

We study a gravity model where a tensionful codimension-one three-brane is embedded on a bulk with infinite transverse length. We find that 4D gravity is induced on the brane already at the classical level if we include higher-curvature (Gauss-Bonnet) terms in the bulk. Consistency conditions appear to require a negative brane tension as well as a negative coupling for the higher-curvature terms.

Bastianelli, Fiorenzo; Corradini, Olindo; Zirotti, Andrea ( 2004 ) - BRST treatment of zero modes for the worldline formalism in curved space - JOURNAL OF HIGH ENERGY PHYSICS - n. volume 0401 (2004) 023 - pp. da 0 a 32 ISSN: 1029-8479 [Articolo in rivista (262) - Articolo su rivista]
Abstract

One-loop quantities in QFT can be computed in an efficient way using the worldline formalism. The latter rests on the ability of calculating 1D path integrals on the circle. In this paper we give a systematic discussion for treating zero modes on the circle of 1D path integrals for both bosonic and supersymmetric nonlinear sigma models, following an approach originally introduced by Friedan. We use BRST techniques and place a special emphasis on the issue of reparametrization invariance. Various examples are extensively analyzed to verify and test the general set-up. In particular, we explicitly check that the chiral anomaly, which can be obtained by the semiclassical approximation of a supersymmetric 1D path integral, does not receive higher order worldline contributions, as implied by supersymmetry.

Corradini, Olindo; Iglesias, Alberto; Kakushadze, Zurab ( 2003 ) - Diluting solutions of the cosmological constant problem - MODERN PHYSICS LETTERS A - n. volume A18 (2003) - pp. da 1343 a 1353 ISSN: 0217-7323 [Articolo in rivista (262) - Articolo su rivista]
Abstract

We discuss the cosmological constant problem in the context of higher codimension brane world scenarios with infinite-volume extra dimensions.

Bastianelli, Fiorenzo; Corradini, Olindo; Zirotti, Andrea ( 2003 ) - Dimensional regularization for N=1supersymmetric sigma models and the worldline formalism - PHYSICAL REVIEW D - n. volume D67 (2003) 104009 - pp. da 1 a 15 ISSN: 0556-2821 [Articolo in rivista (262) - Articolo su rivista]
Abstract

We generalize the worldline formalism to include spin 1/2 fields coupled to gravity. To this purpose we first extend dimensional regularization to supersymmetric nonlinear sigma models in one dimension. We consider a finite propagation time and find that dimensional regularization is a manifestly supersymmetric regularization scheme, since the classically supersymmetric action does not need any counterterm to preserve worldline supersymmetry. We apply this regularization scheme to the worldline description of Dirac fermions coupled to gravity. We first compute the trace anomaly of a Dirac fermion in 4 dimensions, providing an additional check on the regularization with finite propagation time. Then we come to the main topic and consider the one-loop effective action for a Dirac field in a gravitational background. We describe how to represent this effective action as a worldline path integral and compute explicitly the one- and two-point correlation functions, i.e. the spin 1/2 particle contribution to the graviton tadpole and graviton self-energy. These results are presented for the general case of a massive fermion. It is interesting to note that in the worldline formalism the coupling to gravity can be described entirely in terms of the metric, avoiding the introduction of a vielbein. Consequently, the fermion--graviton vertices are always linear in the graviton, just like the standard coupling of fermions to gauge fields.

Corradini, Olindo; Iglesias, Alberto; Kakushadze, Zurab ( 2003 ) - Toward solving the cosmological constant problem? - INTERNATIONAL JOURNAL OF MODERN PHYSICS A - n. volume A18 (2003) - pp. da 3221 a 3262 ISSN: 0217-751X [Articolo in rivista (262) - Articolo su rivista]
Abstract

We discuss the cosmological constant problem in the context of higher codimension brane world scenarios with infinite-volume extra dimensions. In particular, by adding higher curvature terms in the bulk action we are able to find smooth solutions with the property that the 4-dimensional part of the brane world-volume is flat for a range of positive values of the brane tension.

Corradini, Olindo; Iglesias, Alberto; Kakushadze, Zurab; Langfelder, Peter ( 2002 ) - A remark on smoothing out higher codimension branes - MODERN PHYSICS LETTERS A - n. volume A17 (2002) - pp. da 795 a 801 ISSN: 0217-7323 [Articolo in rivista (262) - Articolo su rivista]
Abstract

We discuss some issues arising in studying (linearized) gravity on non-BPS higher codimension branes in an infinite-volume bulk. In particular, such backgrounds are badly singular for codimension-3 and higher delta-function-like branes with non-zero tension. As we discuss in this note, non-trivial issues arise in smoothing out such singularities. Thus, adding higher curvature terms might be necessary in this context.

Corradini, Olindo; Iglesias, Alberto; Kakushadze, Zurab; Langfelder, Peter ( 2001 ) - A remark on nonconformal nonsupersymmetric theories with vanishing vacuum energy density - MODERN PHYSICS LETTERS A - n. volume A16 (2001) - pp. da 1761 a 1773 ISSN: 0217-7323 [Articolo in rivista (262) - Articolo su rivista]
Abstract

We discuss non-conformal non-supersymmetric large N gauge theories with vanishing vacuum energy density to all orders in perturbation theory. These gauge theories can be obtained via a field theory limit of Type IIB D3-branes embedded in orbifolded space-times. We also discuss gravity in this setup.

Corradini, Olindo; Kakushadze, Zurab ( 2001 ) - A solitonic 3-brane in 6D bulk - PHYSICS LETTERS. SECTION B - n. volume B506 (2001) - pp. da 167 a 176 ISSN: 0370-2693 [Articolo in rivista (262) - Articolo su rivista]
Abstract

We construct a solitonic 3-brane solution in the 6-dimensional Einstein-Hilbert-Gauss-Bonnet theory with a (negative) cosmological term. This solitonic brane world is delta-function-like. Near the brane the metric is that for a product of the 4-dimensional flat Minkowski space with a 2-dimensional ``wedge'' with a deficit angle (which depends on the solitonic brane tension). Far from the brane the metric approaches that for a product of the 5-dimensional AdS space and a circle. This solitonic solution exists for a special value of the Gauss-Bonnet coupling (for which we also have a delta-function-like codimension-1 solitonic solution), and the solitonic brane tension can take values in a continuous range. We discuss various properties of this solitonic brane world, including coupling between gravity and matter localized on the brane.

Corradini, Olindo; Iglesias, Alberto; Kakushadze, Zurab; Langfelder, Peter ( 2001 ) - Gravity on a 3-brane in 6D bulk - PHYSICS LETTERS. SECTION B - n. volume B521 (2001) - pp. da 96 a 104 ISSN: 0370-2693 [Articolo in rivista (262) - Articolo su rivista]
Abstract

We study gravity in codimension-2 brane world scenarios with infinite volume extra dimensions. In particular, we consider the case where the brane has non-zero tension. The extra space then is a two-dimensional ``wedge'' with a deficit angle. In such backgrounds we can effectively have the Einstein-Hilbert term on the brane at the classical level if we include higher curvature (Gauss-Bonnet) terms in the bulk. Alternatively, such a term would be generated at the quantum level if the brane matter is not conformal. We study (linearized) gravity in the presence of the Einstein-Hilbert term on the brane in such backgrounds. We find that, just as in the original codimension-2 Dvali-Gabadadze model with a tensionless brane, gravity is almost completely localized on the brane with ultra-light modes penetrating into the bulk.

Bastianelli, Fiorenzo; Corradini, Olindo ( 2001 ) - 6D trace anomalies from quantum mechanical path integrals - PHYSICAL REVIEW D - n. volume D63 (2001) 065005 - pp. da 1 a 11 ISSN: 0556-2821 [Articolo in rivista (262) - Articolo su rivista]
Abstract

We use the recently developed dimensional regularization (DR) scheme for quantum mechanical path integrals in curved space and with a finite time interval to compute the trace anomalies for a scalar field in six dimensions. This application provides a further test of the DR method applied to quantum mechanics. It shows the efficiency in higher loop computations of having to deal with covariant counterterms only, as required by the DR scheme.

Bastianelli, F; Corradini, O.; Van Nieuwenhuizen, P. ( 2000 ) - Dimensional regularization of nonlinear sigma models on a finite time interval - PHYSICS LETTERS. SECTION B - n. volume B494 (2000) - pp. da 161 a 167 ISSN: 0370-2693 [Articolo in rivista (262) - Articolo su rivista]
Abstract

We extend dimensional regularization to the case of compact spaces. Contrary to previous regularization schemes employed for nonlinear sigma models on a finite time interval (``quantum mechanical path integrals in curved space'') dimensional regularization requires only a covariant finite two-loop counterterm. This counterterm is nonvanishing and given by R/8.

Bastianelli, F; Corradini, O.; Van Nieuwenhuizen, P. ( 2000 ) - Dimensional regularization of the path integral in curved space on an infinite time interval - PHYSICS LETTERS. SECTION B - n. volume B490 (2000) - pp. da 154 a 162 ISSN: 0370-2693 [Articolo in rivista (262) - Articolo su rivista]
Abstract

We use dimensional regularization to evaluate quantum mechanical path integrals in arbitrary curved spaces on an infinite time interval. We perform 3-loop calculations in Riemann normal coordinates, and 2-loop calculations in general coordinates. It is shown that one only needs a covariant two-loop counterterm (V_{DR} = R/8) to obtain the same results as obtained earlier in other regularization schemes. It is also shown that the mass term needed in order to avoid infrared divergences explicitly breaks general covariance in the final result.

Corradini, Olindo; Kakushadze, Zurab ( 2000 ) - Localized gravity and higher curvature terms - PHYSICS LETTERS. SECTION B - n. volume B494 (2000) - pp. da 302 a 310 ISSN: 0370-2693 [Articolo in rivista (262) - Articolo su rivista]
Abstract

We consider localization of gravity in smooth domain wall solutions of gravity coupled to a scalar field with a generic potential in the presence of the Gauss-Bonnet term. We discuss conditions on the scalar potential such that domain wall solutions are non-singular. We point out that the presence of the Gauss-Bonnet term does not allow flat solutions with localized gravity that violate the weak energy condition. We also point out that in the presence of the Gauss-Bonnet term infinite tension flat domain walls violate positivity. In fact, for flat solutions unitarity requires that on the solution the scalar potential be bounded below.

Bastianelli, Fiorenzo; Corradini, Olindo ( 1999 ) - Mode regularization of the configuration space path integral in curved space - PHYSICAL REVIEW D - n. volume D60 (1999) 044014 - pp. da 1 a 10 ISSN: 0556-2821 [Articolo in rivista (262) - Articolo su rivista]
Abstract

The path integral representation of the transition amplitude for a particle moving in curved space has presented unexpected challenges since the introduction of path integrals by Feynman fifty years ago. In this paper we discuss and review mode regularization of the configuration space path integral, and present a three loop computation of the transition amplitude to test with success the consistency of such a regularization. Key features of the method are the use of the Lee-Yang ghost fields, which guarantee a consistent treatment of the non-trivial path integral measure at higher loops, and an effective potential specific to mode regularization which arises at two loops. We also perform the computation of the transition amplitude using the regularization of the path integral by time discretization, which also makes use of Lee-Yang ghost fields and needs its own specific effective potential. This computation is shown to reproduce the same final result as the one performed in mode regularization.

Bastianelli, F.; Corradini, O. ( 1997 ) - 't Hooft anomaly matching conditions for generalized symmetries in 2D - PHYSICS LETTERS. SECTION B - n. volume B413 (1997) - pp. da 349 a 354 ISSN: 0370-2693 [Articolo in rivista (262) - Articolo su rivista]
Abstract

The 't Hooft anomaly matching conditions are a standard tool to study and test non-perturbative issues in quantum field theory. We give a new, simple proof of the anomaly matching conditions in 2D Poincare` invariant theories. We consider the case of invariance under a large class of generalized symmetries, which include abelian and non-abelian internal symmetries, space-time symmetries generated by the stress tensor, and W-type of symmetries generated by higher spin currents.