Littérature scientifique sur le sujet « BFV-BRST formalism »

Quantum localization of classical mechanics within the BRST-BFV and BV (or field–antifield) quantization methods are studied. It is shown that a special choice of gauge fixing functions (or BRST-BFV charge) together with the unitary limit leads to Hamiltonian localization in the path integral of the BRST-BFV formalism. In turn, we find that a special choice of gauge fixing functions being proportional to extremals of an initial non-degenerate classical action together with a very special solution of the classical master equation result in Lagrangian localization in the partition function of the BV formalism.

Gauge-invariant systems of a general form with higher order time derivatives of gauge parameters are investigated within the framework of the BFV formalism. Higher order terms of the BRST charge and BRST-invariant Hamiltonian are obtained. It is shown that the identification rules for Lagrangian and Hamiltonian BRST ghost variables depend on the choice of the extension of constraints from the primary constraint surface.

For a wide class of mechanical systems, invariant under gauge transformations with arbitrary higher order time derivatives of gauge parameters, the equivalence of Lagrangian and Hamiltonian BRST formalisms is proved. It is shown that the Ostrogradsky formalism establishes the natural rules to relate the BFV ghost canonical pairs with the ghosts and antighosts introduced by the Lagrangian approach. Explicit relation between corresponding gauge-fixing terms is obtained.

The BRST quantization of particle motion on the hypersurface V N − 1 embedded in Euclidean space R N is carried out both in Hamiltonian and Lagrangian formalism. Using Batalin-Fradkin-Fradkina-Tyutin (BFFT) method, the second class constraints obtained using Hamiltonian analysis are converted into first class constraints. Then using BFV analysis the BRST symmetry is constructed. We have given a simple example of these kind of system. In the end we have discussed Batalin-Vilkovisky formalism in the context of this (BFFT modified) system.

We study systematically finite BRST-BFV transformations in the generalized Hamiltonian formalism. We present explicitly their Jacobians and the form of a solution to the compensation equation determining the functional field dependence of finite Fermionic parameters, necessary to generate an arbitrary finite change of gauge-fixing functions in the path integral.

The BRST quantization of the U(1) gauged model of FJ-type chiral boson for [Formula: see text] and [Formula: see text] are performed using the Batalin–Fradkin–Vilkovisky formalism. BFV formalism converts the second-class algebra into an effective first-class algebra with the help of auxiliary fields. Explicit expressions of the BRST charge, the involutive Hamiltonian, and the preserving BRST symmetry action are given and the full quantization has been carried through. For [Formula: see text], this Hamiltonian gives the gauge invariant Lagrangian including the well-known Wess–Zumino term, while for [Formula: see text] the corresponding Lagrangian has the additional new type of the Wess–Zumino term. The spectra in both cases have been analysed and the Wess–Zumino actions in terms of auxiliary fields are identified.

We study systematically finite BRST-BFV transformations in Sp(2)-extended generalized Hamiltonian formalism. We present explicitly their Jacobians and the form of a solution to the compensation equation determining the functional field dependence of finite Fermionic parameters, necessary to generate arbitrary finite change of gauge-fixing functions in the path integral.

We study finite field-dependent BRST–BFV transformations for dynamical systems with first- and second-class constraints within the generalized Hamiltonian formalism. We find explicitly their Jacobians and the form of a solution to the compensation equation necessary for generating an arbitrary finite change of gauge-fixing functionals in the path integral.

The BRST quantization of the Abelian Proca model is performed using the Batalin–Fradkin–Tyutin and the Batalin-Fradkin-Vilkovisky formalism. First, the BFT Hamiltonian method is applied in order to systematically convert a second class constraint system of the model into an effectively first class one by introducing new fields. In finding the involutive Hamiltonian we adopt a new approach which is simpler than the usual one. We also show that in our model the Dirac brackets of the phase space variables in the original second class constraint system are exactly the same as the Poisson brackets of the corresponding modified fields in the extended phase space due to the linear character of the constraints comparing the Dirac or Faddeev–Jackiw formalisms. Then, according to the BFV formalism we obtain that the desired resulting Lagrangian preserving BRST symmetry in the standard local gauge fixing procedure naturally includes the Stückelberg scalar related to the explicit gauge symmetry breaking effect due to the presence of the mass term. We also analyze the nonstandard nonlocal gauge fixing procedure.

Sistemas geralmente covariantes têm uma Hamiltoniana canônica nula, não é necessário encontrar na Hamiltoniana efetiva para determinar sua evolução dinâmica.Esta Hamiltoniana efetiva é dependente do gauge e sua forma varia com a escolha do gauge. Dirac propôs um método baseado em teoria de grupos para determinar a Hamiltoniana efetiva. Nós propomos um método baseado em teorias de gauge, segundo o formalismo BRST-BFV, para determiná-la. Aplicaremos o método à partícula relativística e a um modelo com dois tempos, também geralmente covariante. Para a partícula relativística com massa nula e spin N/2 encontraremos a Hamiltoniana efetiva nos gauges canônicos propostos por Dirac, chamados as formas da dinâmica: instante, frente de onda e pontual. Para isso, determinaremos a função fermiônica fixadora de gauge apropriada no formalismo BRST-BFV . A função fermiônica fixadora de gauge quebra as simetrias da ação original, tanto as simetrias locais quanto as globais, de forma que a Hamiltoniana efetiva é invariante por um grupo de simetria menor que o da ação clássica. No caso da física com dois tempos, o grupo de simetria da ação clássica, é o grupo conforme SO(d,2), maior que o grupo de Poincaré da partícula relativística. A ação também é invariante pela simetria local OSp(N\\2). Utilizando a mesma técnica aplicada à partícula relativística determinaremos, após as fixações dos gauges, as Hamiltonianas efetivas. Veremos que suas simetrias são menores que as simetrias da ação original, porém maiores que as da partícula relativística. Encontraremos uma Hamiltoniana não-relativística arbitrária, invariante por rotações em um espaço com (d-1) domensões espaciais e spin N/2. Neste trabalho, procuramos resolver alguns problemas que aparecem na física com dois tempos formulada por I. Bars, tais como a arbitrariedade das Hamiltonianas e das escolhas de gauge que levam a elas. Bars escolheu arbitrariamente as Hamiltonianas como combinações de geradores do grupo conforme, e fez escolhas de gauge complicadas e arbitrárias. Nós apresentamos escolhas de gauge mais simples que, de modo sistemático, resultam em Hamiltonianas com grupos de simetrias menores que os da ação original. Além disso, o resultado descrito no parágrafo acima, i.e., a Hamiltoniana arbitrária e com spin N/2, não havia sido obtido antes.
A general covariant system hás a vanishing canonical Hamiltonian and its time evolution is determined by na effective Hamiltonian. This effective Hamiltonian is gauge dependent and its form depends on the gauge on the gauge choice. Dirac has proposed a method based on gauge theories, according to the BRST-BFV formalism to determine it. This method Will be applied both to the relativistic particle and to a two-times model. For the massless relativistic and spin N/2 we Will showhow to get the effective Hamiltonian for the canonical gauges discussed by Dirac, called the forms of dynamics: instant, front and point. We Will find the appropriate gauge fixing function in the BRST-BFV formalism. The gauge fixing function breaks the symmetries of the original action, the local and the global symmetries, so that the effective Hamiltonian is invariant by a gauge symmetry groupwhich is smaller than the gauge symmetry group of the classical action. In the two times physics, the symmetry group of the classical action is the conformal group SO(d,2), which is larger than the Poincares group of the relativistic particle. The action is also invariant by the local symmetry OSp(N\\2). By using the same technique used in the relativistic particle, we Will determine the effective Hamiltonians, after the gauges had been fixed. We Will see that their symmetries are smaller than the original action symmetries, but they are larger than the symmetry group of the relativistic particle. We Will find a non-relativistic arbitrary Hamiltonian, invariant by rotations in a space with (d-1) dimensions and spin N/2. In this work, we tried to solve some problems that appeared in two times physics elaborated by I Bars, Just like the arbitrariness of Hamiltonians and the choices of gauges, which lead to them. Bars has chosen the Hamiltonians arbitrarily as combinations of the generators of the conformal group and has chosen complicated and arbitrary gauges. We have presented simple gauge choices, in which, in a systematic way, arise in Hamiltonians with symmetry groups that are smaller than the former paragraph, i. e. , na arbitrary Hamiltonian with spin N/2, hadnt been obtained before.

In this thesis, we investigate deformation theory and moduli theory of coisotropic submanifolds in Jacobi manifolds. Originally introduced by Kirillov as local Lie algebras with one dimensional fibers, Jacobi manifolds encompass, unifying and generalizing, locally conformal symplectic manifolds, locally conformal Poisson manifolds, and non-necessarily coorientable contact manifolds. We attach an L-infinity-algebra to any coisotropic submanifold in a Jacobi manifold. Our construction generalizes and unifies analogous constructions by Oh-Park (symplectic case), Cattaneo-Felder (Poisson case), and Le-Oh (locally conformal symplectic case). As a completely new case we also associate an L-infinity-algebra with any coisotropic submanifold in a contact manifold. The L-infinity-algebra of a coisotropic submanifold S controls the formal coisotropic deformation problem of S, even under Hamiltonian equivalence, and provides criteria both for the obstructedness and for the unobstructedness at the formal level. Additionally we prove that if a certain condition ("fiberwise entireness") is satisfied then the L-infinity-algebra controls the non-formal coisotropic deformation problem, even under Hamiltonian equivalence. We associate a BFV-complex with any coisotropic submanifold in a Jacobi manifold. Our construction extends an analogous construction by Schatz in the Poisson setting, and in particular it also applies in the locally conformal symplectic/Poisson setting and the contact setting. Unlike the L-infinity-algebra, we prove that, with no need of any restrictive hypothesis, the BFV-complex of a coisotropic submanifold S controls the non-formal coisotropic deformation problem of S, even under both Hamiltonian equivalence and Jacobi equivalence. Notwithstanding the differences there is a close relation between the approaches to the coisotropic deformation problem via L-infinity-algebra and via BFV-complex. Indeed both the L-infinity-algebra and the BFV-complex of a coisotropic submanifold S provide a cohomological reduction of S. Moreover they are L-infinity quasi-isomorphic and so they encode equally well the moduli space of formal coisotropic deformations of S under Hamiltonian equivalence. In addition we exhibit two examples of coisotropic submanifolds in the contact setting whose coisotropic deformation problem is obstructed at the formal level. Further we provide a conceptual explanation of this phenomenon both in terms of the L-infinity-algebra and in terms of the BFV-complex.