Thermodynamics in dynamical Chern-Simons modified gravity with canonical scalar field

AbstractThe present study reports reconstruction schemes for tachyon, k-essence and dilaton scalar field model of Dark Energy (DE) through Tsallis holographic dark fluid under the framework of Chern–Simons modified gravity. Reproducing the conservation equation for a coupled model with interaction term $Q=3H{b}^{2}{\rho }_{m}$ we have reconstructed the different scalar fields and the corresponding potentials. In the case of tachyon, ΛCDM fixed point is attained under this cosmological settings. Considering k-essence in this interacting situation, we have derived some constraints on the interaction term as well as Tsallis holographic dark energy parameter. Reconstructing dilaton scalar field, we have studied the behavior of scalar field and potential. In all those cases, the reconstructed Equation of State (EoS) parameters have been plotted and when computed for current universe z = 0 are found to be consistent with various observational data including Planck + WP + BAO. The only exception is a particular case of reconstructed k-essence model where phantom behavior is apparent, but its numerical value is deviated from the bounce set by the observations. Expressions for different constraints have been obtained and evolutionary behavior of reconstructed scalar fields and potentials for the various cases have been pictorially presented. Finally, we have developed a functional relationship between Hubble parameter and redshift and optimized the parameter values through χ2 minimization using the observed Hubble parameter values from Hai Yu et al. 2018 ApJ856 3.

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THE EDGE STATES OF THE BF SYSTEM AND THE LONDON EQUATIONS

International Journal of Modern Physics A ◽

10.1142/s0217751x9300028x ◽

1993 ◽

Vol 08 (04) ◽

pp. 723-752 ◽

Cited By ~ 30

Author(s):

A.P. BALACHANDRAN ◽

P. TEOTONIO-SOBRINHO

Keyword(s):

Scalar Field ◽

Scaling Limit ◽

Quantum Hall ◽

Simons Theory ◽

Massless Scalar ◽

Electromagnetic Current ◽

Massless Scalar Field ◽

Edge States ◽

Chern Simons ◽

London Equations

It is known that the 3D Chern–Simons interaction describes the scaling limit of a quantum Hall system and predicts edge currents in a sample with boundary, the currents generating a chiral U(1) Kac-Moody algebra. It is no doubt also recognized that, in a somewhat similar way, the 4D BF interaction (with B a two-form, dB the dual *j of the electromagnetic current, and F the electromagnetic field form) describes the scaling limit of a superconductor. We show in this paper that there are edge excitations in this model as well for manifolds with boundaries. They are the modes of a scalar field with invariance under the group of diffeomorphisms (diffeos) of the bounding spatial two-manifold. Not all diffeos of this group seem implementable by operators in quantum theory, the implementable group being a subgroup of volume-preserving diffeos. The BF system in this manner can lead to the w1+∞ algebra and its variants. Lagrangians for fields on the bounding manifold which account for the edge observables on quantization are also presented. They are the analogs of the (1+1)-dimensional massless scalar field Lagrangian describing the edge modes of an Abelian Chern-Simons theory with a disk as the spatial manifold. We argue that the addition of “Maxwell” terms constructed from F∧*F and dB∧*dB does not affect the edge states, and that the augmented Lagrangian has an infinite number of conserved charges—the aforementioned scalar field modes—localized at the edges. This Lagrangian is known to describe London equations and a massive vector field. A (3+1)-dimensional generalization of the Hall effect involving vortices coupled to B is also proposed.

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Massive scalar field perturbation on Kerr black holes in dynamical Chern–Simons gravity

The European Physical Journal C ◽

10.1140/epjc/s10052-021-09249-8 ◽

2021 ◽

Vol 81 (5) ◽

Author(s):

Shao-Jun Zhang

Keyword(s):

Black Holes ◽

Black Hole ◽

Scalar Field ◽

Massive Scalar ◽

Coupling Constant ◽

Field Mass ◽

Field Perturbation ◽

Massive Scalar Field ◽

Kerr Black Holes ◽

Chern Simons

AbstractWe study massive scalar field perturbation on Kerr black holes in dynamical Chern–Simons gravity by performing a $$(2+1)$$ ( 2 + 1 ) -dimensional simulation. Object pictures of the wave dynamics in time domain are obtained. The tachyonic instability is found to always occur for any nonzero black hole spin and any scalar field mass as long as the coupling constant exceeds a critical value. The presence of the mass term suppresses or even quench the instability. The quantitative dependence of the onset of the tachyonic instability on the coupling constant, the scalar field mass and the black hole spin is given numerically.

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Geodetic precession and strong gravitational lensing in dynamical Chern–Simons-modified gravity

Classical and Quantum Gravity ◽

10.1088/0264-9381/27/22/225006 ◽

2010 ◽

Vol 27 (22) ◽

pp. 225006 ◽

Cited By ~ 17

Author(s):

Songbai Chen ◽

Jiliang Jing

Keyword(s):

Gravitational Lensing ◽

Modified Gravity ◽

Geodetic Precession ◽

Strong Gravitational Lensing ◽

Chern Simons

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Cosmological Implications of the Generalized Entropy Based Holographic Dark Energy Models in Dynamical Chern-Simons Modified Gravity

Advances in High Energy Physics ◽

10.1155/2019/1287932 ◽

2019 ◽

Vol 2019 ◽

pp. 1-9 ◽

Cited By ~ 10

Author(s):

M. Younas ◽

Abdul Jawad ◽

Saba Qummer ◽

H. Moradpour ◽

Shamaila Rani

Keyword(s):

Dark Energy ◽

Equation Of State ◽

Modified Gravity ◽

Dark Energy Model ◽

State Parameter ◽

Energy Model ◽

Evolutionary Equation ◽

Energy Models ◽

Equation Of State Parameter ◽

Chern Simons

Recently, Tsallis, Rényi, and Sharma-Mittal entropies have widely been used to study the gravitational and cosmological setups. We consider a flat FRW universe with linear interaction between dark energy and dark matter. We discuss the dark energy models using Tsallis, Rényi, and Sharma-Mittal entropies in the framework of Chern-Simons modified gravity. We explore various cosmological parameters (equation of state parameter, squared sound of speed ) and cosmological plane (ωd-ωd′, where ωd′ is the evolutionary equation of state parameter). It is observed that the equation of state parameter gives quintessence-like nature of the universe in most of the cases. Also, the squared speed of sound shows stability of Tsallis and Rényi dark energy model but unstable behavior for Sharma-Mittal dark energy model. The ωd-ωd′ plane represents the thawing region for all dark energy models.

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Inflationary models with a canonical scalar field

Series on the Foundations of Natural Science and Technology - Scalar Field Cosmology ◽

10.1142/9789811205088_0001 ◽

2019 ◽

pp. 3-16

Keyword(s):

Scalar Field ◽

Inflationary Models ◽

Canonical Scalar Field

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Cosmological implications of dark energy models in modified gravity

International Journal of Geometric Methods in Modern Physics ◽

10.1142/s0219887818500342 ◽

2018 ◽

Vol 15 (03) ◽

pp. 1850034 ◽

Cited By ~ 2

Author(s):

Nadeem Azhar ◽

Abdul Jawad ◽

Sarfraz Ahmad ◽

Iftikhar Ahmed

Keyword(s):

Dark Energy ◽

Modified Gravity ◽

Cold Dark Matter ◽

Cosmological Parameters ◽

Accelerated Expansion ◽

Pilgrim Dark Energy ◽

Energy Models ◽

Expansion Of The Universe ◽

Qcd Ghost Dark Energy ◽

Chern Simons

We discuss the interacting modified QCD ghost dark energy and generalized ghost pilgrim dark energy with cold dark matter in the framework of dynamical Chern–Simons modified gravity. We investigate the cosmological parameters such as Hubble parameter, deceleration parameter and equation of state. We also discuss the physical significance of various cosmological planes like [Formula: see text] and statefinders. It is found that the results of cosmological parameters as well as planes explain the accelerated expansion of the Universe and are compatible with observational data.

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