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Related papers: Generalised DBI-Quintessence

200 papers

We employ a generalized Dicke model to study theoretically the quantum criticality of an extended two-level atomic ensemble interacting with a single-mode quantized light field. Effective Hamiltonians are derived and diagonalized to…

Quantum Physics · Physics 2007-10-01 Yong Li , Z. D. Wang , C. P. Sun

K-essence has been proposed as a possible means of explaining the coincidence problem of the Universe beginning to accelerate only at the present epoch. We carry out a comprehensive dynamical systems analysis of the k-essence models given…

Astrophysics · Physics 2009-11-07 Michael Malquarti , Edmund J Copeland , Andrew R Liddle

We derive a quantum version of the classical-optics Wiener-Khintchine theorem within the framework of detection of phase-space displacements with a suitably designed quantum ruler. A phase-pace based quantum mutual coherence function is…

Quantum Physics · Physics 2022-09-07 Ainara Álvarez-Marcos , Alfredo Luis

Phase is a basic ingredient for quantum states since quantum mechanics uses complex numbers to describe quantum states. In this letter, we introduce a rigorous framework to quantify the phase of quantum states. To do so, we regard phase as…

Quantum Physics · Physics 2023-08-10 Jianwei Xu

The application of geometry to physics has provided us with new insightful information about many physical theories such as classical mechanics, general relativity, and quantum geometry (quantum gravity). The geometry also plays an…

Quantum Physics · Physics 2015-06-19 Hoshang Heydari

We examine a quintessence model with a modified exponential potential given by $V(\phi) = V_0(1+e^{-\lambda \phi})$. Unlike quintessence with a standard exponential potential, our model can yield an acceptable accelerated expansion at late…

Cosmology and Nongalactic Astrophysics · Physics 2016-12-02 Hui-Yiing Chang , Robert J. Scherrer

Quintessence is a canonical scalar field introduced to explain the late-time cosmic acceleration. The cosmological dynamics of quintessence is reviewed, paying particular attention to the evolution of the dark energy equation of state w.…

General Relativity and Quantum Cosmology · Physics 2015-06-15 Shinji Tsujikawa

Sequential dynamical systems (SDS) are used to model a wide range of processes occurring on graphs or networks. The dynamics of such discrete dynamical systems is completely encoded by their phase space, a directed graph whose vertices and…

Dynamical Systems · Mathematics 2017-02-03 Raffaele Rani , Poul G. Hjorth

Starting from the usual bosonic membrane action, we develop the geometry suitable for the description of $p$-brane backgrounds. Using the tools of generalized geometry we derive the generalization of string open-closed relations.…

High Energy Physics - Theory · Physics 2014-09-05 Branislav Jurco , Peter Schupp , Jan Vysoky

Distinct from the dynamical phase, in a cyclic evolution, a system's state may acquire an additional component, a.k.a. geometric phase. The latter is a manifestation of a closed path in state space. Geometric phases underlie various…

In this letter, we study the condition for a generalized DBI action providing a quintom scenario of dark energy. We consider a development of string-inspired quintom by introducing non-minimal coupling. Then we show that the bouncing…

High Energy Physics - Theory · Physics 2008-11-26 M. R. Setare , J. Sadeghi , A. Banijamali

In this paper, we have presented a model of the FLRW universe filled with matter and dark energy fluids, by assuming an ansatz that deceleration parameter is a linear function of the Hubble constant. This results in a time-dependent DP…

General Relativity and Quantum Cosmology · Physics 2021-08-02 Gopi Kant Goswami , Anirudh Pradhan , Aroonkumar Beesham

Tracking quintessence, in a spatially flat and isotropic space-time with a minimally coupled canonical scalar field and an asymptotically inverse power-law potential $V(\varphi)\propto\varphi^{-p}$, $p>0$, as $\varphi\rightarrow0$, is…

General Relativity and Quantum Cosmology · Physics 2024-02-06 Artur Alho , Claes Uggla , John Wainwright

As an alternative to the popular parametrisations of the dark energy equation of state, we construct a quintessence model where the scalar field has a linear dependence on the number of e-folds. Constraints on more complex models are…

Cosmology and Nongalactic Astrophysics · Physics 2021-12-17 Vitor da Fonseca , Tiago Barreiro , Nelson J. Nunes

The phase structure of QCD remains an open fundamental problem of standard model physics. In particular at finite density, our knowledge is limited. Yet, numerous model studies point towards a rich and complex phase diagram at large…

High Energy Physics - Phenomenology · Physics 2025-10-14 Fabian Rennecke

We apply the Wigner function formalism from quantum optics via two approaches, Wootters' discrete Wigner function and the generalized Wigner function, to detect quantum phase transitions in critical spin-$\tfrac{1}{2}$ systems. We develop a…

Quantum Physics · Physics 2019-09-09 Zakaria Mzaouali , Steve Campbell , Morad El Baz

In this paper, we present an exactly solvable phase transition model in which the phase transition is purely statistically derived. The phase transition in this model is a generalized Bose-Einstein condensation. The exact expression of the…

Statistical Mechanics · Physics 2015-05-14 Wu-Sheng Dai , Mi Xie

The dissipative Dicke model exhibits a fascinating out-of-equilibrium many-body phase transition as a function of a coupling between a driven photonic cavity and numerous two-level atoms. We study the effect of a time-dependent parametric…

Quantum Gases · Physics 2015-08-19 R. Chitra , Oded Zilberberg

We analyse a DGP brane filled with a k-essence field and assume the k-field evolving linearly with the cosmic time of the brane. We then solve analytically the Friedmann equation and deduce the different behaviour of the brane at the low…

Cosmology and Nongalactic Astrophysics · Physics 2010-11-11 Mariam Bouhmadi-Lopez , Luis Chimento

We present a new parameterization of quintessence potentials for dark energy based directly upon the dynamical properties of the equations of motion. Such parameterization arises naturally once the equations of motion are written as a…

General Relativity and Quantum Cosmology · Physics 2018-11-07 Nandan Roy , Alma X. Gonzalez-Morales , L. Arturo Urena-Lopez