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Related papers: Backreaction in spinor QED and decoherence functio…

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Using the Schwinger-Keldysh (closed time path or CTP) and Feynman-Vernon influence functional formalisms we obtain a Langevin equation for the description of the charged particle creation in electric field and of backreaction of charged…

High Energy Physics - Theory · Physics 2007-05-23 Shaisultanov R

We continue our earlier investigation of the backreaction problem in semiclassical gravity with the Schwinger-Keldysh or closed-time-path (CTP) functional formalism using the language of the decoherent history formulation of quantum…

General Relativity and Quantum Cosmology · Physics 2016-08-31 Esteban Calzetta , B. L. Hu

We derive quantum kinetic equations for fermions in a homogeneous time-dependent background in presence of decohering collisions, by use of the Schwinger-Keldysh CTP-formalism. The quantum coherence (between particles and antiparticles) is…

High Energy Physics - Phenomenology · Physics 2009-03-24 Matti Herranen , Kimmo Kainulainen , Pyry Matti Rahkila

We study the transition from the full quantum mechanical description of physical systems to an approximate classical stochastic one. Our main tool is the identification of the closed-time-path (CTP) generating functional of Schwinger and…

General Relativity and Quantum Cosmology · Physics 2016-08-31 Charis Anastopoulos

We describe how the concepts of quantum open systems and the methods of closed-time-path (CTP) effective action and influence functional (IF) can be usefully applied to the analysis of statistical mechanical problems involving quantum…

General Relativity and Quantum Cosmology · Physics 2007-05-23 B. L. Hu

We consider quantum electrodynamics with additional coupling of spinor fields to the space-time independent axial vector violating both Lorentz and CPT symmetries. The Fock-Schwinger proper time method is used to calculate the one-loop…

High Energy Physics - Theory · Physics 2011-07-19 Yu. A. Sitenko , K. Yu. Rulik

A generalization of the action principle of classical mechanics, motivated by the Closed Time Path (CTP) scheme of quantum field theory, is presented to deal with initial condition problems and dissipative forces. The similarities of the…

High Energy Physics - Theory · Physics 2015-06-22 Janos Polonyi

We find the Bogoliubov coefficient from the tunneling boundary condition on a charged particle coupled to a static electric field $E_0 sech^2 (z/L)$ and, using the regularization scheme in Phys. Rev. D 78, 105013 (2008), obtain the exact…

High Energy Physics - Theory · Physics 2014-11-20 Sang Pyo Kim , Hyun Kyu Lee , Yongsung Yoon

We consider the quantum kinetic-theory description for interacting massive spin-half fermions using the Wigner function formalism. We derive a general kinetic theory description assuming that the spin effects appear at the classical and…

High Energy Physics - Theory · Physics 2023-09-11 Arpan Das , Wojciech Florkowski , Avdhesh Kumar , Radoslaw Ryblewski , Rajeev Singh

An effective action technique for the time evolution of a closed system consisting of one or more mean fields interacting with their quantum fluctuations is presented. By marrying large $N$ expansion methods to the Schwinger-Keldysh closed…

High Energy Physics - Phenomenology · Physics 2008-11-26 Fred Cooper , Salman Habib , Yuval Kluger , Emil Mottola , Juan Pablo Paz , Paul R. Anderson

If violation of Lorentz and CPT symmetry is introduced into the fermion sector of conventional quantum electrodynamics, then the Chern-Simons term is radiatively induced with finite nonzero coefficient, as well as the Maxwell term is with…

High Energy Physics - Theory · Physics 2014-11-18 Yu. A. Sitenko

Using closed-time path two-particle irreducible coarse-grained effective action (CTP 2PI CGEA) techniques, we study the response of an open interacting electronic system to time-dependent external electromagnetic fields. We show that the…

Strongly Correlated Electrons · Physics 2009-12-03 J. Peralta-Ramos , E. Calzetta

The nonequilibrium dynamics of quantum fields is studied in inflationary cosmology, with particular emphasis on applications to the problem of post-inflation reheating. The Schwinger-Keldysh closed-time-path (CTP) formalism is utilized…

General Relativity and Quantum Cosmology · Physics 2007-05-23 Stephen A. Ramsey

We present a detailed field theoretic description of those collective degrees of freedom (CDF) which are relevant to study macroscopic quantum dynamics of a quasi-one-dimensional ferromagnetic domain wall. We apply spin coherent state path…

Mesoscale and Nanoscale Physics · Physics 2009-11-07 Junya Shibata , Shin Takagi

We compute the gravitational effective action by integrating out quantum matter fields in a weak gravitational field, using the Schwinger-Keldysh (in-in) formalism. We pay particular attention to the role of the initial quantum state in the…

High Energy Physics - Theory · Physics 2017-11-15 M. Elías , F. D. Mazzitelli , L. G. Trombetta

We extend the Post-Minkowskian (PM) effective field theory (EFT) approach to incorporate conservative and dissipative radiation-reaction effects in a unified framework. This is achieved by implementing the Schwinger-Keldysh "in-in"…

High Energy Physics - Theory · Physics 2023-02-15 Gregor Kälin , Jakob Neef , Rafael A. Porto

Functional methods can be applied to the quantum effective action to efficiently determine counterterms and matching conditions for effective field theories. We extend the toolbox to two-loop order and beyond and show how to evaluate the…

High Energy Physics - Phenomenology · Physics 2025-08-20 Javier Fuentes-Martín , Adrián Moreno-Sánchez , Ajdin Palavrić , Anders Eller Thomsen

We consider a scalar field theory in Minkowski spacetime and define a coarse grained Closed Time Path (CTP) effective action by integrating quantum fluctuations of wavelengths shorter than a critical value. We derive an exact CTP…

High Energy Physics - Theory · Physics 2014-11-18 Diego A. R. Dalvit , Francisco D. Mazzitelli

Some field theoretical aspects, such as the effective action and Schwinger pair production, are critically reviewed in strong QED. The difference of the boundary conditions on the solutions of the field equation is discussed to result in…

High Energy Physics - Theory · Physics 2015-05-13 Sang Pyo Kim

The application of functional integral methods and the Hubbard--Stratonovich transformation to the Hubbard model is discussed. For the attractive case, using a simple gauge transformation of the superconducting order parameter field, the…

Condensed Matter · Physics 2007-05-23 H. J. Schulz
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