scholarly journals AN ALTERNATIVE CONSTRUCTION OF THE QUANTUM ACTION FOR SUPERGRAVITY

2000 ◽  
Vol 15 (20) ◽  
pp. 1307-1320 ◽  
Author(s):  
N. DJEGHLOUL ◽  
M. TAHIRI
Keyword(s):  
Classical Action ◽  
Invariant Extension ◽  
Alternative Construction ◽  
Simple Supergravity ◽  
Quantum Action ◽  
Full Quantum ◽  
Invariant Quantum

We develop a method to derive the on-shell invariant quantum action of the simple supergravity in such a way that the quartic ghost interactions term is explicity determined. First, we reinvestigate the simple supergravity in terms of a principal superfiber bundle. This gives rise to the closed geometrical BRST algebra. Therefore we determine the open BRST algebra, which realizes the invariance of the classical action. Then, given a prescription to build the full quantum action, we obtain the quantum BRST algebra. Together with the constructed quantum action this allows us to recover the auxiliary fields and the invariant extension of the classical action.

BRST and Anti-BRST Symmetry in Topological BF Theories

1997 ◽  
Vol 12 (18) ◽  
pp. 3153-3170 ◽  
Author(s):  
M. Tahiri
Keyword(s):  
Brst Symmetry ◽  
Point Of View ◽  
Ghost Number ◽  
Time Dimension ◽  
Direct Construction ◽  
Superspace Formalism ◽  
Structure Equations ◽  
Quantum Action ◽  
Full Quantum ◽  
Invariant Quantum

We realize the quantization of arbitrary-dimensional non-Abelian BF theories from the point of view of both the BRST symmetry and anti-BRST symmetry. The method relies on the possibility of enlarging the system of fields occurring in such theories by auxiliary fields introduced geometrically in terms of a superspace formalism. The off-shell nilpotency of the BRST and anti-BRST transformations of these fields is automatically guaranteed, thanks to the structure equations and the Bianchi identities. From this follows a direct construction of the BRST invariant full quantum action which leads, after the elimination of the auxiliary fields, to the same quantum action obtained in the context of the Batalin–Vilkovisky formalism. We also discuss how the constructed BRST invariant quantum action is anti-BRST invariant. In addition, we show that the non-Abelian BF theory in any space–time dimension possesses a vector supersymmetry of ghost number +1.

scholarly journals ON AUXILIARY FIELDS IN BF THEORIES

2005 ◽  
Vol 20 (22) ◽  
pp. 1703-1708 ◽  
Author(s):  
D. GHAFFOR ◽  
M. TAHIRI
Keyword(s):  
Classical Action ◽  
Invariant Extension ◽  
Brst Operator ◽  
Quantum Action ◽  
Arbitrary Dimensions ◽  
Complete Quantum

We discuss the structure of auxiliary fields for non-Abelian BF theories in arbitrary dimensions. By modifying the classical BRST operator, we build the on-shell invariant complete quantum action. Therefore, we introduce the auxiliary fields which close the BRST algebra and lead to the invariant extension of the classical action.

QUANTUM CLOSED STRINGS FROM MINIMAL AREA

1990 ◽  
Vol 05 (32) ◽  
pp. 2753-2762 ◽  
Author(s):  
BARTON ZWIEBACH
Keyword(s):  
Exact Solution ◽  
Quantum Theory ◽  
String Theory ◽  
Master Equation ◽  
Closed String ◽  
Feynman Rules ◽  
Higher Genus ◽  
Quantum Action ◽  
Full Quantum ◽  
Minimal Area

Canonical and factorizable off-shell amplitudes for covariant closed string theory can be obtained from string diagrams of minimal area. Evidence is given that all higher genus minimal area string diagrams can be built using vertices and propagators, implying that the off-shell amplitudes arise from the Feynman rules of a full quantum theory of closed strings. The quantum action gives an exact solution of the full master equation of Batalin and Vilkoviski.

scholarly journals Examples of enhanced quantization: Bosons, fermions and anyons

2014 ◽  
Vol 29 (22) ◽  
pp. 1450119
Author(s):  
T. C. Adorno ◽  
J. R. Klauder
Keyword(s):  
Hilbert Space ◽  
Coherent States ◽  
Canonical Quantization ◽  
Action Functional ◽  
Classical Action ◽  
Unitary Transformations ◽  
Classical Quantum ◽  
Quantum Action ◽  
Space Vectors ◽  
Gaussian Vectors

Enhanced quantization offers a different classical/quantum connection than that of canonical quantization in which ℏ > 0 throughout. This result arises when the only allowed Hilbert space vectors allowed in the quantum action functional are coherent states, which leads to the classical action functional augmented by additional terms of order ℏ. Canonical coherent states are defined by unitary transformations of a fixed, fiducial vector. While Gaussian vectors are commonly used as fiducial vectors, they cannot be used for all systems. We focus on choosing fiducial vectors for several systems including bosons, fermions and anyons.

TOPOLOGICAL YANG-MILLS THEORY WITH VECTOR AND ANTISYMMETRIC TENSOR FIELDS

1995 ◽  
Vol 10 (25) ◽  
pp. 3649-3662 ◽  
Author(s):  
DAE SUNG HWANG
Keyword(s):  
Antisymmetric Tensor ◽  
Tensor Fields ◽  
Brst Transformation ◽  
Classical Action ◽  
Yang Mills ◽  
Transformation Rules ◽  
The Matrix ◽  
Extended Field ◽  
Quantum Action ◽  
Matrix Derivative

We study a system composed of vector and second rank antisymmetric tensor gauge fields in the superconnection framework. We incorporate the matrix derivative of non-commutative geometry in order to induce the topological Yang-Mills theory. In this structure we get the BRST and anti-BRST transformation rules from one horizontality condition, and obtain the topological classical action naturally from the extended field strength. We obtain its quantum action through the BRST formalism.

PHOTON PART OF QUANTUM ACTION FUNCTIONAL IN QED

1994 ◽  
Vol 09 (15) ◽  
pp. 1423-1428
Author(s):  
YU.A. GOLFAND
Keyword(s):  
Electromagnetic Field ◽  
General Theory ◽  
Functional Equations ◽  
Action Functional ◽  
Classical Action ◽  
Special Representation ◽  
Quantum Action ◽  
Field Strengths

The photon part of the quantum action functional in QED is investigated using the effective functional Seff instead of the classical action Sph in the standard functional equations. All powers of the electromagnetic field strengths appear in Seff, so the special representation of the quantum action, proposed recently7 must be constructed according to the general theory. The dependence of Seff on the electromagnetic field strengths has been investigated.

scholarly journals Generalization of Faddeev–Popov rules in Yang–Mills theories: N = 3,4 BRST symmetries

2018 ◽  
Vol 33 (03) ◽  
pp. 1850006 ◽  
Author(s):  
Alexander Reshetnyak
Keyword(s):  
Irreducible Representation ◽  
Classical Model ◽  
Brst Symmetry ◽  
Classical Action ◽  
Gauge Transformations ◽  
Yang Mills ◽  
Gauge Dependence ◽  
Change Of Variables ◽  
Gauge Fixing ◽  
Quantum Action

The Faddeev–Popov rules for a local and Poincaré-covariant Lagrangian quantization of a gauge theory with gauge group are generalized to the case of an invariance of the respective quantum actions, [Formula: see text], with respect to [Formula: see text]-parametric Abelian SUSY transformations with odd-valued parameters [Formula: see text], [Formula: see text] and generators [Formula: see text]: [Formula: see text], for [Formula: see text], implying the substitution of an [Formula: see text]-plet of ghost fields, [Formula: see text], instead of the parameter, [Formula: see text], of infinitesimal gauge transformations: [Formula: see text]. The total configuration spaces of fields for a quantum theory of the same classical model coincide in the [Formula: see text] and [Formula: see text] symmetric cases. The superspace of [Formula: see text] SUSY irreducible representation includes, in addition to Yang–Mills fields [Formula: see text], [Formula: see text] ghost odd-valued fields [Formula: see text], [Formula: see text] and [Formula: see text] even-valued [Formula: see text] for [Formula: see text], [Formula: see text]. To construct the quantum action, [Formula: see text], by adding to the classical action, [Formula: see text], of an [Formula: see text]-exact gauge-fixing term (with gauge fermion), a gauge-fixing procedure requires [Formula: see text] additional fields, [Formula: see text]: antighost [Formula: see text], [Formula: see text] even-valued [Formula: see text], 3 odd-valued [Formula: see text] and Nakanishi–Lautrup [Formula: see text] fields. The action of [Formula: see text] transformations on new fields as [Formula: see text]-irreducible representation space is realized. These transformations are the [Formula: see text] BRST symmetry transformations for the vacuum functional, [Formula: see text]. The space of all fields [Formula: see text] proves to be the space of an irreducible representation of the fields [Formula: see text] for [Formula: see text]-parametric SUSY transformations, which contains, in addition to [Formula: see text] the [Formula: see text] ghost–antighost, [Formula: see text], even-valued, [Formula: see text], odd-valued [Formula: see text] and [Formula: see text] fields. The quantum action is constructed by adding to [Formula: see text] an [Formula: see text]-exact gauge-fixing term with a gauge boson, [Formula: see text]. The [Formula: see text] SUSY transformations are by [Formula: see text] BRST transformations for the vacuum functional, [Formula: see text]. The procedures are valid for any admissible gauge. The equivalence with [Formula: see text] BRST-invariant quantization method is explicitly found. The finite [Formula: see text] BRST transformations are derived and the Jacobians for a change of variables related to them but with field-dependent parameters in the respective path integral are calculated. They imply the presence of a corresponding modified Ward identity related to a new form of the standard Ward identities and describe the problem of a gauge-dependence. An introduction into diagrammatic Feynman techniques for [Formula: see text] BRST invariant quantum actions for Yang–Mills theory is suggested.

Fusion and Breakup Reactions of 17S + 208Pb and 15C + 232ThHalo Nuclei Systems

2015 ◽  
Vol 11 (2) ◽  
pp. 2972-2978
Author(s):  
Fouad A. Majeed ◽  
Yousif A. Abdul-Hussien
Keyword(s):  
Experimental Data ◽  
Cross Section ◽  
Fusion Reaction ◽  
Fusion Cross Section ◽  
Reaction Cross ◽  
Recent Experimental Data ◽  
Barrier Distribution ◽  
Coupled Channel ◽  
Total Fusion ◽  
Full Quantum

In this study the calculations of the total fusion reaction cross section have been performed for fusion reaction systems 17F + 208Pb and 15C + 232Th which involving halo nuclei by using a semiclassical approach.The semiclassical treatment is comprising the WKB approximation to describe the relative motion between target and projectile nuclei, and Continuum Discretized Coupled Channel (CDCC) method to describe the intrinsic motion for both target and projectile nuclei. For the same of comparsion a full quantum mechanical clacualtions have been preforemd using the (CCFULL) code. Our theorticalrestuls are compared with the full quantum mechaincialcalcuations and with the recent experimental data for the total fusion reaction  checking the stability of the distancesThe coupled channel calculations of the total fusion cross section σfus, and the fusion barrier distribution Dfus. The comparsion with experiment proves that the semiclassiacl approach adopted in the present work reproduce the experimental data better that the full quantal mechanical calcautions. 

Quantum description of light–matter coupling

2017 ◽  
Author(s):  
Alexey V. Kavokin ◽  
Jeremy J. Baumberg ◽  
Guillaume Malpuech ◽  
Fabrice P. Laussy
Keyword(s):  
Cavity Mode ◽  
Optical Field ◽  
Level System ◽  
Bloch Equations ◽  
Optical Bloch Equations ◽  
Matter Coupling ◽  
Matter Interaction ◽  
Light Matter Interaction ◽  
Full Quantum ◽  
The Ideal

In this chapter we study with the tools developed in Chapter 3 the basic models that are the foundations of light–matter interaction. We start with Rabi dynamics, then consider the optical Bloch equations that add phenomenologically the lifetime of the populations. As decay and pumping are often important, we cover the Lindblad form, a correct, simple and powerful way to describe various dissipation mechanisms. Then we go to a full quantum picture, quantizing also the optical field. We first investigate the simpler coupling of bosons and then culminate with the Jaynes–Cummings model and its solution to the quantum interaction of a two-level system with a cavity mode. Finally, we investigate a broader family of models where the material excitation operators differ from the ideal limits of a Bose and a Fermi field.

scholarly journals Scattering in Terms of Bohmian Conditional Wave Functions for Scenarios with Non-Commuting Energy and Momentum Operators

Entropy ◽  
2021 ◽  
Vol 23 (4) ◽  
pp. 408
Author(s):  
Matteo Villani ◽  
Guillermo Albareda ◽  
Carlos Destefani ◽  
Xavier Cartoixà ◽  
Xavier Oriols
Keyword(s):  
Single Particle ◽  
Degrees Of Freedom ◽  
Single Photon ◽  
Open Quantum Systems ◽  
Wave Functions ◽  
Practical Application ◽  
Light Matter Interaction ◽  
Pure States ◽  
Energy And Momentum ◽  
Full Quantum

Without access to the full quantum state, modeling quantum transport in mesoscopic systems requires dealing with a limited number of degrees of freedom. In this work, we analyze the possibility of modeling the perturbation induced by non-simulated degrees of freedom on the simulated ones as a transition between single-particle pure states. First, we show that Bohmian conditional wave functions (BCWFs) allow for a rigorous discussion of the dynamics of electrons inside open quantum systems in terms of single-particle time-dependent pure states, either under Markovian or non-Markovian conditions. Second, we discuss the practical application of the method for modeling light–matter interaction phenomena in a resonant tunneling device, where a single photon interacts with a single electron. Third, we emphasize the importance of interpreting such a scattering mechanism as a transition between initial and final single-particle BCWF with well-defined central energies (rather than with well-defined central momenta).

Sign in / Sign up

Export Citation Format

Share Document