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Using a new method--statefinder diagnostic which can differ one dark energy model from the others, we investigate in this letter the dynamics of Born-Infeld(B-I) type dark energy model. The evolutive trajectory of B-I type dark energy with…

High Energy Physics - Theory · Physics 2008-11-25 Z. G. Huang , H. Q. Lu

We consider the problem of estimating the temperature $ T $ of a very cold equilibrium sample. The temperature estimates are drawn from measurements performed on a quantum probe strongly coupled to it. We model this scenario by resorting to…

We present an analysis of the phase space of cosmological models based on a non minimal coupling between the geometry and a fermionic condensate. We obtain that the strong constraint coming from the Dirac equations allows a detailed design…

General Relativity and Quantum Cosmology · Physics 2018-04-20 Sante Carloni , Stefano Vignolo , Roberto Cianci

The Pair Approximation method is applied to studies of the bilayer and multilayer magnetic systems with simple cubic structure. The method allows to take into account quantum effects related with non-Ising couplings. The paper adopts the…

Statistical Mechanics · Physics 2013-04-09 Karol Szałowski , Tadeusz Balcerzak

Scalar fields in the early Universe are mostly discussed in two limits: either in equilibrium or completely decoupled. In this work we discuss scenarios where there are scalar fields that are not in equilibrium, but for which the coupling…

High Energy Physics - Phenomenology · Physics 2025-07-30 V. Knapp-Perez , Gopolang Mohlabeng , Michael Ratz , Tim M. P. Tait

In this paper it is studied the influence of a minimal thermal environment on the dynamics of a quantum harmonic oscillator (labelled A), prepared in a coherent state. The environment itself consists of a second oscillator (labelled B),…

Quantum Physics · Physics 2021-08-31 A. Vidiella-Barranco

In this manuscript, we examine the cosmological significance of the new agegraphic dark energy model by investigating different cosmological parameters such as the equation of state parameter, $\omega_{D}-\omega^{\prime}_{D}$ and the $r-s$…

General Relativity and Quantum Cosmology · Physics 2025-01-03 Madiha Ajmal , M. Sharif

We investigate the equilibration and thermalization properties of quantum systems interacting with a finite dimensional environment. By exploiting the concept of time averaged states, we introduce a completely positive map which allows to…

Quantum Physics · Physics 2012-11-27 A. Smirne , E. -M. Laine , H. -P. Breuer , J. Piilo , B. Vacchini

Using dynamical systems methods, we describe the evolution of a minimally coupled scalar field and a Friedmann-Lemaitre-Robertson-Walker universe in the context of general relativity, which is relevant for inflation and late-time…

General Relativity and Quantum Cosmology · Physics 2015-06-11 Valerio Faraoni , Charles S. Protheroe

The notion of "paired" fermions is central to important condensed matter phenomena such as superconductivity and superfluidity. While the concept is widely used and its physical meaning is clear there exists no systematic and mathematical…

Quantum Physics · Physics 2009-11-13 Christina V. Kraus , Michael M. Wolf , J. Ignacio Cirac , Geza Giedke

The pairwise entanglement is exactly examined in the spin-1/2 Ising-Heisenberg double-tetrahedral chain with different Land\'e g-factors of the Ising and Heisenberg spins at zero and finite temperatures. It is shown that the phenomenon…

Statistical Mechanics · Physics 2020-07-24 Lucia Galisova

The interaction of a discrete state coupled to a continuum is a longstanding problem of major interest in different areas of quantum and classical physics. In Hermitian models, several dynamical decoupling schemes have been suggested, in…

Quantum Physics · Physics 2018-01-17 Stefano Longhi

In this paper we put forward a running coupling scenario for describing the interaction between dark energy and dark matter. The dark sector interaction in our scenario is free of the assumption that the interaction term $Q$ is proportional…

Cosmology and Nongalactic Astrophysics · Physics 2015-03-19 Yun-He Li , Xin Zhang

By a detector, one has in mind a point particle with internal energy levels, which when set in motion on a generic trajectory can get excited due to its interaction with a quantum field. Detectors have often been considered as a helpful…

General Relativity and Quantum Cosmology · Physics 2016-12-28 L. Sriramkumar

Thermal phenomena in quantum field theory can be detected with the aid of particle detectors coupled to quantum fields along stationary worldlines, by testing whether the response of such a detector satisfies the detailed balance version of…

Mathematical Physics · Physics 2016-04-01 Christopher J. Fewster , Benito A. Juárez-Aubry , Jorma Louko

The time evolution of thermal states of a mirror released from a tight harmonic trap is studied. After the release no dissipation is assumed to be present and the mirror is, after a time delay, kicked into a momentum superposition state.…

Quantum Physics · Physics 2011-09-12 Ole Steuernagel

We study a quantum theory based on two assumptions: In the intrinsic frame of reference of an isolated, macroscopic system, (i) the system has no global motion and is not entangled with any other system, (ii) time evolution of statevectors…

Quantum Physics · Physics 2016-09-08 Wen-ge Wang

We investigate the consequences of non-minimal gravitational coupling to matter and study how it differs from the case of minimal coupling by choosing certain simple forms for the nature of coupling, The values of the parameters are…

Cosmology and Nongalactic Astrophysics · Physics 2011-02-03 Shruti Thakur , Anjan A Sen , T. R. Seshadri

Quantum dynamics of coherent states is studied within quantum field theory using two complementary methods: by organizing the evolution as a Taylor series in elapsed time and by perturbative expansion in coupling within the…

High Energy Physics - Theory · Physics 2021-10-13 Lasha Berezhiani , Michael Zantedeschi

We study the dynamics of two interacting two-level systems (qubits) having one of them isolated and the other coupled to a single mode electromagnetic field in a thermal state. The field plays the role of a small environment, in contrast to…

Quantum Physics · Physics 2022-11-01 G. L. Deçordi , A. Vidiella-Barranco