CONSTRAINED FERMIONIC MODELS IN NON-TRIVIAL TOPOLOGICAL SECTORS

1992 ◽  
Vol 07 (24) ◽  
pp. 2179-2188 ◽  
Author(s):  
ENRIQUE F. MORENO
Keyword(s):  
Path Integral ◽  
Degrees Of Freedom ◽  
Central Charge ◽  
Coulomb Gas ◽  
Effective Theory ◽  
Fermionic Model ◽  
Topological Sector ◽  
Integral Treatment ◽  
Background Charge

We study a constrained fermionic model involving non-trivial topological gauge configurations. After a path-integral treatment of the topologically trivial degrees of freedom we show that the resulting effective theory is equivalent to a Coulomb gas theory with a "background charge" at infinity plus a b, c ghost system. The Virasoro central charge of the theory is found to be independent of the topological sector.

Dirac oscillator in a uniform electric field: Path integral treatment

2019 ◽  
Vol 34 (30) ◽  
pp. 1950246
Author(s):  
Hassene Bada ◽  
Mekki Aouachria
Keyword(s):  
Energy Spectrum ◽  
Electric Field ◽  
Path Integral ◽  
Uniform Electric Field ◽  
Two Dimensional ◽  
Dirac Oscillator ◽  
Fermionic Model ◽  
Internal Motions ◽  
Integral Treatment ◽  
The One

In this paper, the propagator of a two-dimensional Dirac oscillator in the presence of a uniform electric field is derived by using the path integral technique. The fact that the globally named approach is used in this work redirects, beforehand, our search for the propagator of the Dirac equation to that of the propagator of its quadratic form. The internal motions relative to the spin are represented by two fermionic oscillators, which are described by Grassmannian variables, according to Schwinger’s fermionic model. Once the integration over the anticommuting variables (Grassmannian variables) is accomplished, the problem becomes the one of finding a non-relativistic propagator with only bosonic variables. The energy spectrum of the electron and the corresponding eigenspinors are also obtained in this work.

scholarly journals CONFORMALLY INVARIANT CONSTRAINED FERMION MODELS

1990 ◽  
Vol 05 (12) ◽  
pp. 2313-2330 ◽  
Author(s):  
D. CABRA ◽  
E. MORENO ◽  
C. von REICHENBACH
Keyword(s):  
Path Integral ◽  
Central Charge ◽  
Effective Theory ◽  
Conformally Invariant

We construct constrained fermion models within the path-integral framework. By an appropriate choice of constraints we obtain an effective theory with central charge in the minimal unitary series, its supersymmetric generalization and other well-known series. We also discuss the relation between these constrained fermion models and gauged Wess-Zumino-Witten models.

scholarly journals Parafermionization, bosonization, and critical parafermionic theories

2021 ◽  
Vol 2021 (4) ◽  
Author(s):  
Yuan Yao ◽  
Akira Furusaki
Keyword(s):  
Field Theory ◽  
Conformal Field Theory ◽  
Degrees Of Freedom ◽  
Lattice Models ◽  
Partition Functions ◽  
Minimal Models ◽  
Fermionic Model ◽  
Conformal Field ◽  
Critical Theories ◽  
Wigner Transformation

AbstractWe formulate a ℤk-parafermionization/bosonization scheme for one-dimensional lattice models and field theories on a torus, starting from a generalized Jordan-Wigner transformation on a lattice, which extends the Majorana-Ising duality atk= 2. The ℤk-parafermionization enables us to investigate the critical theories of parafermionic chains whose fundamental degrees of freedom are parafermionic, and we find that their criticality cannot be described by any existing conformal field theory. The modular transformations of these parafermionic low-energy critical theories as general consistency conditions are found to be unconventional in that their partition functions on a torus transform differently from any conformal field theory whenk >2. Explicit forms of partition functions are obtained by the developed parafermionization for a large class of critical ℤk-parafermionic chains, whose operator contents are intrinsically distinct from any bosonic or fermionic model in terms of conformal spins and statistics. We also use the parafermionization to exhaust all the ℤk-parafermionic minimal models, complementing earlier works on fermionic cases.

scholarly journals A path integral formulation for particle detectors: the Unruh-DeWitt model as a line defect

2021 ◽  
Vol 2021 (3) ◽  
Author(s):  
Ivan M. Burbano ◽  
T. Rick Perche ◽  
Bruno de S. L. Torres
Keyword(s):  
Path Integral ◽  
Degrees Of Freedom ◽  
Wilson Line ◽  
Transition Probability ◽  
Relativistic Quantum ◽  
Quantum Fields ◽  
Line Defect ◽  
Particle Detectors ◽  
Nonlocal Operators ◽  
Detector Model

Abstract Particle detectors are an ubiquitous tool for probing quantum fields in the context of relativistic quantum information (RQI). We formulate the Unruh-DeWitt (UDW) particle detector model in terms of the path integral formalism. The formulation is able to recover the results of the model in general globally hyperbolic spacetimes and for arbitrary detector trajectories. Integrating out the detector’s degrees of freedom yields a line defect that allows one to express the transition probability in terms of Feynman diagrams. Inspired by the light-matter interaction, we propose a gauge invariant detector model whose associated line defect is related to the derivative of a Wilson line. This is another instance where nonlocal operators in gauge theories can be interpreted as physical probes for quantum fields.

W-ALGEBRA REALIZATIONS AND W-GRAVITY ANOMALIES

1991 ◽  
Vol 06 (32) ◽  
pp. 2995-3003 ◽  
Author(s):  
C. M. HULL ◽  
L. PALACIOS
Keyword(s):  
Path Integral ◽  
Current Algebra ◽  
Gravity Anomalies ◽  
Normal Ordering ◽  
Path Integral Quantization ◽  
Transformation Rules ◽  
Higher Derivative ◽  
Quantum Current ◽  
Boson Model ◽  
Background Charge

The coupling of scalars fields to chiral W3 gravity is reviewed. In general the quantum current algebra generated by the spin-two and three currents does not close when the "natural" regularization (corresponding to the normal ordering with respect to the modes of ∂ϕi) is used, and the non-closure reflects matter-dependent anomalies in the path integral quantization. We consider the most general modification of the current, involving higher derivative "background charge" terms, and find the conditions for them to form a closed algebra in the "natural" regularization. These conditions can be satisfied only for the two-boson model. In that case, it is possible to cancel all the matter-dependent anomalies by adding finite local counter terms to the action and modifying the transformation rules of the fields.

scholarly journals Soft-collinear effective theory: BRST formulation

2021 ◽  
Vol 81 (4) ◽  
Author(s):  
Sudhaker Upadhyay ◽  
Bhabani Prasad Mandal
Keyword(s):  
Degrees Of Freedom ◽  
Brst Symmetry ◽  
Symmetry Transformation ◽  
Gauge Condition ◽  
Effective Theory ◽  
Hard Interaction ◽  
Soft Collinear Effective Theory ◽  
Parameter Field ◽  
Definite Structure ◽  
Gauge Conditions

AbstractWe provide a BRST formalism for the soft-collinear effective theory describing interactions of soft and collinear degrees of freedom in the presence of a hard interaction. In particular, we develop a BRST symmetry transformation for SCET theory. We further generalize the BRST formulation by making the transformation parameter field dependent. This establishes a mapping between several SCET actions consistently when defined in different gauge conditions. In fact, a definite structure of gauge-fixed actions corresponding to any particular gauge condition can be generated for SCET theory using our formulation.

Path‐integral treatment of multi‐mode vibronic coupling

1994 ◽  
Vol 100 (2) ◽  
pp. 926-937 ◽  
Author(s):  
Stefan Krempl ◽  
Manfred Winterstetter ◽  
Heiko Plöhn ◽  
Wolfgang Domcke
Keyword(s):  
Path Integral ◽  
Vibronic Coupling ◽  
Integral Treatment ◽  
Multi Mode

scholarly journals INFINITE STATISTICS, SYMMETRY BREAKING AND COMBINATORIAL HIERARCHY

2009 ◽  
Vol 24 (18) ◽  
pp. 1425-1435 ◽  
Author(s):  
VLADIMIR SHEVCHENKO
Keyword(s):  
Symmetry Breaking ◽  
Mechanical Model ◽  
Degrees Of Freedom ◽  
High Energy ◽  
Low Energy ◽  
Effective Theory ◽  
Quantum Mechanical ◽  
Hierarchy Problem ◽  
Induced Gravity ◽  
Large Numbers

The physics of symmetry breaking in theories with strongly interacting quanta obeying infinite (quantum Boltzmann) statistics known as quons is discussed. The picture of Bose/Fermi particles as low energy excitations over nontrivial quon condensate is advocated. Using induced gravity arguments, it is demonstrated that the Planck mass in such low energy effective theory can be factorially (in number of degrees of freedom) larger than its true ultraviolet cutoff. Thus, the assumption that statistics of relevant high energy excitations is neither Bose nor Fermi but infinite can remove the hierarchy problem without necessity to introduce any artificially large numbers. Quantum mechanical model illustrating this scenario is presented.

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