Special Issue "Cosmological Inflation, Dark Matter and Dark Energy"

A special issue of Symmetry (ISSN 2073-8994).

Deadline for manuscript submissions: 30 June 2019

Special Issue Editor

Guest Editor
Prof. Dr. Kazuharu Bamba

Division of Human Support System, Faculty of Symbiotic Systems Science, Fukushima University, Fukushima 960-1296, Japan
Website | E-Mail
Phone: +81-24-503-3263
Fax: +81-24-598-3187
Interests: modified theories of gravity; dark energy; cosmology; particle-theory and field-theory models of the early universe; electric and magnetic fields; quantum aspects of black holes, evaporation, thermodynamics

Special Issue Information

Dear Colleagues,

Based on the recent cosmological observations, such as Type Ia Supernovae, cosmic microwave background (CMB) radiation large scale structure, baryon acoustic oscillations (BAO) and weak lensing, the universe has experienced the accelerated phase of its expansion not only in the early universe but also in the present time. The former is called "inflation" and the latter is called "the late-time cosmic acceleration". It is also well known that the three energy components of the universe are dark energy (about 68%), dark matter (about 27%) and baryon (about 5%).

A number of studies have been executed for the origins of the field to realize inflation, dark matter and dark energy, which are most fundamental problems in modern physics and cosmology. The future detection of the primordial gravitational waves is strongly expected in order to know the energy scale of the inflationary phase. Moreover, there are two possibilities for the origin of dark matter, namely, new particles in particle-theory models beyond the standard model and astrophysical objects. Furthermore, there have been proposed two representative studies for the true character of dark energy. One is the introduction of some unknown matter called dark energy with the negative pressure in the framework of general relativity. The other is the modification of gravity at large scales, leading to the so-called geometrical dark energy.

The main aim of this special issue is to understand various cosmological aspects of inflation, dark matter and dark energy. In addition to the phenomenological approaches, more fundamental studies are considered from higher-dimensional theories of gravity, quantum gravity and quantum cosmology, physics in the early universe, quantum field theories and gauge field theories in curved spacetime, and strings, branes and holographic principle. It is very pleased to receive submissions to this special issue on inflation, dark matter, dark energy and related foundations of physics.

Prof. Dr. Kazuharu Bamba
Guest Editor

Manuscript Submission Information

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Keywords

  • inflation
  • dark matter
  • dark energy
  • cosmology
  • modified gravity theories
  • higher-dimensional theories of gravity
  • quantum gravity and quantum cosmology
  • primordial gravitational waves
  • physics in the early universe
  • particle-theory models beyond the standard model
  • quantum field theories and gauge field theories in curved spacetime
  • strings, branes and holographic principle

Published Papers (12 papers)

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Research

Open AccessArticle
Effect of Quantum Gravity on the Stability of Black Holes
Symmetry 2019, 11(5), 631; https://doi.org/10.3390/sym11050631
Received: 10 April 2019 / Revised: 25 April 2019 / Accepted: 26 April 2019 / Published: 5 May 2019
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Abstract
We investigate the massive vector field equation with the WKB approximation. The tunneling mechanism of charged bosons from the gauged super-gravity black hole is observed. It is shown that the appropriate radiation consistent with black holes can be obtained in general under the [...] Read more.
We investigate the massive vector field equation with the WKB approximation. The tunneling mechanism of charged bosons from the gauged super-gravity black hole is observed. It is shown that the appropriate radiation consistent with black holes can be obtained in general under the condition that back reaction of the emitted charged particle with self-gravitational interaction is neglected. The computed temperatures are dependant on the geometry of black hole and quantum gravity. We also explore the corrections to the charged bosons by analyzing tunneling probability, the emission radiation by taking quantum gravity into consideration and the conservation of charge and energy. Furthermore, we study the quantum gravity effect on radiation and discuss the instability and stability of black hole. Full article
(This article belongs to the Special Issue Cosmological Inflation, Dark Matter and Dark Energy)
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Open AccessArticle
The Lanczos Equation on Light-Like Hypersurfaces in a Cosmologically Viable Class of Kinetic Gravity Braiding Theories
Symmetry 2019, 11(5), 616; https://doi.org/10.3390/sym11050616
Received: 11 April 2019 / Accepted: 22 April 2019 / Published: 2 May 2019
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Abstract
We discuss junction conditions across null hypersurfaces in a class of scalar–tensor gravity theories (i) with second-order dynamics, (ii) obeying the recent constraints imposed by gravitational wave propagation, and (iii) allowing for a cosmologically viable evolution. These requirements select kinetic gravity braiding models [...] Read more.
We discuss junction conditions across null hypersurfaces in a class of scalar–tensor gravity theories (i) with second-order dynamics, (ii) obeying the recent constraints imposed by gravitational wave propagation, and (iii) allowing for a cosmologically viable evolution. These requirements select kinetic gravity braiding models with linear kinetic term dependence and scalar field-dependent coupling to curvature. We explore a pseudo-orthonormal tetrad and its allowed gauge fixing with one null vector standing as the normal and the other being transversal to the hypersurface. We derive a generalization of the Lanczos equation in a 2 + 1 decomposed form, relating the energy density, current, and isotropic pressure of a distributional source to the jumps in the transverse curvature and transverse derivative of the scalar. Additionally, we discuss a scalar junction condition and its implications for the distributional source. Full article
(This article belongs to the Special Issue Cosmological Inflation, Dark Matter and Dark Energy)
Open AccessArticle
Hadronic and Hadron-Like Physics of Dark Matter
Symmetry 2019, 11(4), 587; https://doi.org/10.3390/sym11040587
Received: 29 March 2019 / Revised: 15 April 2019 / Accepted: 17 April 2019 / Published: 23 April 2019
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Abstract
The problems of simple elementary weakly interacting massive particles (WIMPs) appeal to extend the physical basis for nonbaryonic dark matter. Such extension involves more sophisticated dark matter candidates from physics beyond the Standard Model (BSM) of elementary particles. We discuss several models of [...] Read more.
The problems of simple elementary weakly interacting massive particles (WIMPs) appeal to extend the physical basis for nonbaryonic dark matter. Such extension involves more sophisticated dark matter candidates from physics beyond the Standard Model (BSM) of elementary particles. We discuss several models of dark matter, predicting new colored, hyper-colored or techni-colored particles and their accelerator and non-accelerator probes. The nontrivial properties of the proposed dark matter candidates can shed new light on the dark matter physics. They provide interesting solutions for the puzzles of direct and indirect dark matter search. Full article
(This article belongs to the Special Issue Cosmological Inflation, Dark Matter and Dark Energy)
Open AccessArticle
Cosmological Consequences of New Dark Energy Models in Einstein-Aether Gravity
Symmetry 2019, 11(4), 509; https://doi.org/10.3390/sym11040509
Received: 16 February 2019 / Revised: 18 March 2019 / Accepted: 28 March 2019 / Published: 8 April 2019
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Abstract
In this paper, we reconstruct various solutions for the accelerated universe in the Einstein-Aether theory of gravity. For this purpose, we obtain the effective density and pressure for Einstein-Aether theory. We reconstruct the Einstein-Aether models by comparing its energy density with various newly [...] Read more.
In this paper, we reconstruct various solutions for the accelerated universe in the Einstein-Aether theory of gravity. For this purpose, we obtain the effective density and pressure for Einstein-Aether theory. We reconstruct the Einstein-Aether models by comparing its energy density with various newly proposed holographic dark energy models such as Tsallis, Rényi and Sharma-Mittal. For this reconstruction, we use two forms of the scale factor, power-law and exponential forms. The cosmological analysis of the underlying scenario has been done by exploring different cosmological parameters. This includes equation of state parameter, squared speed of sound and evolutionary equation of state parameter via graphical representation. We obtain some favorable results for some values of model parameters Full article
(This article belongs to the Special Issue Cosmological Inflation, Dark Matter and Dark Energy)
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Open AccessArticle
Alternative Uses for Quantum Systems and Devices
Symmetry 2019, 11(4), 462; https://doi.org/10.3390/sym11040462
Received: 31 January 2019 / Revised: 1 March 2019 / Accepted: 7 March 2019 / Published: 2 April 2019
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Abstract
Quantum optical systems and devices were analyzed to verify theories both predicting new particles on flat spacetime, and for the verification of Planck-scale physics for cosmological investigation. Full article
(This article belongs to the Special Issue Cosmological Inflation, Dark Matter and Dark Energy)
Open AccessArticle
Spacetime Symmetry and LemaîTre Class Dark Energy Models
Symmetry 2019, 11(1), 90; https://doi.org/10.3390/sym11010090
Received: 14 December 2018 / Revised: 9 January 2019 / Accepted: 11 January 2019 / Published: 15 January 2019
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Abstract
We present the regular cosmological models of the Lemaître class with time-dependent and spatially inhomogeneous vacuum dark energy, which describe relaxation of the cosmological constant from its value powering inflation to the final non-zero value responsible for the present acceleration in the frame [...] Read more.
We present the regular cosmological models of the Lemaître class with time-dependent and spatially inhomogeneous vacuum dark energy, which describe relaxation of the cosmological constant from its value powering inflation to the final non-zero value responsible for the present acceleration in the frame of one self-consistent theoretical scheme based on the algebraic classification of stress-energy tensors and spacetime symmetry directly related to their structure. Cosmological evolution starts with the nonsingular non-simultaneous de Sitter bang, followed by the Kasner-type anisotropic expansion, and goes towards the present de Sitter state. Spacetime symmetry provides a mechanism of reducing cosmological constant to a certain non-zero value involving the holographic principle which singles out the special class of the Lemaître dark energy models with the global structure of the de Sitter spacetime. For this class cosmological evolution is guided by quantum evaporation of the cosmological horizon whose dynamics entirely determines the final value of the cosmological constant. For the choice of the density profile modeling vacuum polarization in a spherical gravitational field and the GUT scale for the inflationary value of cosmological constant, its final value agrees with that given by observations. Anisotropy grows quickly at the postinflationary stage, then remains constant and decreases to A < 10 6 when the vacuum density starts to dominate. Full article
(This article belongs to the Special Issue Cosmological Inflation, Dark Matter and Dark Energy)
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Open AccessArticle
Tsallis, Rényi and Sharma-Mittal Holographic Dark Energy Models in Loop Quantum Cosmology
Symmetry 2018, 10(11), 635; https://doi.org/10.3390/sym10110635
Received: 7 October 2018 / Revised: 28 October 2018 / Accepted: 31 October 2018 / Published: 13 November 2018
Cited by 3 | PDF Full-text (758 KB) | HTML Full-text | XML Full-text
Abstract
The cosmic expansion phenomenon is being studied through the interaction of newly proposed dark energy models (Tsallis, Rényi and Sharma-Mittal holographic dark energy (HDE) models) with cold dark matter in the framework of loop quantum cosmology. We investigate different cosmic implications such as [...] Read more.
The cosmic expansion phenomenon is being studied through the interaction of newly proposed dark energy models (Tsallis, Rényi and Sharma-Mittal holographic dark energy (HDE) models) with cold dark matter in the framework of loop quantum cosmology. We investigate different cosmic implications such as equation of state parameter, squared sound speed and cosmological plane (ω d - ω d , ω d and ω d represent the equation of state (EoS) parameter and its evolution, respectively). It is found that EoS parameter exhibits quintom like behavior of the universe for all three models of HDE. The squared speed of sound represents the stable behavior of Rényi HDE and Sharma-Mittal HDE at the latter epoch while unstable behavior for Tsallis HDE. Moreover, ω d - ω d plane lies in the thawing region for all three HDE models. Full article
(This article belongs to the Special Issue Cosmological Inflation, Dark Matter and Dark Energy)
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Open AccessFeature PaperArticle
Dark Matter as a Non-Relativistic Bose–Einstein Condensate with Massive Gravitons
Symmetry 2018, 10(10), 520; https://doi.org/10.3390/sym10100520
Received: 15 September 2018 / Revised: 13 October 2018 / Accepted: 15 October 2018 / Published: 17 October 2018
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Abstract
We confront a non-relativistic Bose–Einstein Condensate (BEC) model of light bosons interacting gravitationally either through a Newtonian or a Yukawa potential with the observed rotational curves of 12 dwarf galaxies. The baryonic component is modeled as an axisymmetric exponential disk and its characteristics [...] Read more.
We confront a non-relativistic Bose–Einstein Condensate (BEC) model of light bosons interacting gravitationally either through a Newtonian or a Yukawa potential with the observed rotational curves of 12 dwarf galaxies. The baryonic component is modeled as an axisymmetric exponential disk and its characteristics are derived from the surface luminosity profile of the galaxies. The purely baryonic fit is unsatisfactory, hence a dark matter component is clearly needed. The rotational curves of five galaxies could be explained with high confidence level by the BEC model. For these galaxies, we derive: (i) upper limits for the allowed graviton mass; and (ii) constraints on a velocity-type and a density-type quantity characterizing the BEC, both being expressed in terms of the BEC particle mass, scattering length and chemical potential. The upper limit for the graviton mass is of the order of 10 26 eV / c 2 , three orders of magnitude stronger than the limit derived from recent gravitational wave detections. Full article
(This article belongs to the Special Issue Cosmological Inflation, Dark Matter and Dark Energy)
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Open AccessFeature PaperArticle
Dark Energy and Dark Matter Interaction: Kernels of Volterra Type and Coincidence Problem
Symmetry 2018, 10(9), 411; https://doi.org/10.3390/sym10090411
Received: 20 August 2018 / Revised: 14 September 2018 / Accepted: 15 September 2018 / Published: 18 September 2018
Cited by 1 | PDF Full-text (283 KB) | HTML Full-text | XML Full-text
Abstract
We study a new exactly solvable model of coupling of the Dark Energy and Dark Matter, in the framework of which the kernel of non-gravitational interaction is presented by the integral Volterra-type operator well-known in the classical theory of fading memory. Exact solutions [...] Read more.
We study a new exactly solvable model of coupling of the Dark Energy and Dark Matter, in the framework of which the kernel of non-gravitational interaction is presented by the integral Volterra-type operator well-known in the classical theory of fading memory. Exact solutions of this isotropic homogeneous cosmological model were classified with respect to the sign of the discriminant of the cubic characteristic polynomial associated with the key equation of the model. Energy-density scalars of the Dark Energy and Dark Matter, the Hubble function and acceleration parameter are presented explicitly; the scale factor is found in quadratures. Asymptotic analysis of the exact solutions has shown that the Big Rip, Little Rip, Pseudo Rip regimes can be realized with the specific choice of guiding parameters of the model. We show that the Coincidence problem can be solved if we consider the memory effect associated with the interactions in the Dark Sector of the universe. Full article
(This article belongs to the Special Issue Cosmological Inflation, Dark Matter and Dark Energy)
Open AccessFeature PaperArticle
Topological Gravity Motivated by Renormalization Group
Symmetry 2018, 10(9), 396; https://doi.org/10.3390/sym10090396
Received: 15 August 2018 / Revised: 6 September 2018 / Accepted: 7 September 2018 / Published: 11 September 2018
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Abstract
Recently, we have proposed models of topological field theory including gravity in Mod. Phys. Lett. A 2016, 31, 1650213 and Phys. Rev. D 2017, 96, 024009, in order to solve the problem of the cosmological constant. The Lagrangian densities [...] Read more.
Recently, we have proposed models of topological field theory including gravity in Mod. Phys. Lett. A 2016, 31, 1650213 and Phys. Rev. D 2017, 96, 024009, in order to solve the problem of the cosmological constant. The Lagrangian densities of the models are BRS (Becchi-Rouet-Stora) exact and therefore the models can be regarded as topological theories. In the models, the coupling constants, including the cosmological constant, look as if they run with the scale of the universe and its behavior is very similar to the renormalization group. Motivated by these models, we propose new models with an the infrared fixed point, which may correspond to the late time universe, and an ultraviolet fixed point, which may correspond to the early universe. In particular, we construct a model with the solutions corresponding to the de Sitter space-time both in the ultraviolet and the infrared fixed points. Full article
(This article belongs to the Special Issue Cosmological Inflation, Dark Matter and Dark Energy)
Open AccessArticle
Decaying Dark Energy in Light of the Latest Cosmological Dataset
Symmetry 2018, 10(9), 372; https://doi.org/10.3390/sym10090372
Received: 2 August 2018 / Revised: 13 August 2018 / Accepted: 21 August 2018 / Published: 1 September 2018
Cited by 2 | PDF Full-text (458 KB) | HTML Full-text | XML Full-text
Abstract
Decaying Dark Energy models modify the background evolution of the most common observables, such as the Hubble function, the luminosity distance and the Cosmic Microwave Background temperature–redshift scaling relation. We use the most recent observationally-determined datasets, including Supernovae Type Ia and Gamma Ray [...] Read more.
Decaying Dark Energy models modify the background evolution of the most common observables, such as the Hubble function, the luminosity distance and the Cosmic Microwave Background temperature–redshift scaling relation. We use the most recent observationally-determined datasets, including Supernovae Type Ia and Gamma Ray Bursts data, along with H ( z ) and Cosmic Microwave Background temperature versus z data and the reduced Cosmic Microwave Background parameters, to improve the previous constraints on these models. We perform a Monte Carlo Markov Chain analysis to constrain the parameter space, on the basis of two distinct methods. In view of the first method, the Hubble constant and the matter density are left to vary freely. In this case, our results are compatible with previous analyses associated with decaying Dark Energy models, as well as with the most recent description of the cosmological background. In view of the second method, we set the Hubble constant and the matter density to their best fit values obtained by the Planck satellite, reducing the parameter space to two dimensions, and improving the existent constraints on the model’s parameters. Our results suggest that the accelerated expansion of the Universe is well described by the cosmological constant, and we argue that forthcoming observations will play a determinant role to constrain/rule out decaying Dark Energy. Full article
(This article belongs to the Special Issue Cosmological Inflation, Dark Matter and Dark Energy)
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Open AccessArticle
New Holographic Dark Energy Model in Brans-Dicke Theory
Symmetry 2018, 10(5), 153; https://doi.org/10.3390/sym10050153
Received: 17 April 2018 / Revised: 4 May 2018 / Accepted: 4 May 2018 / Published: 11 May 2018
Cited by 2 | PDF Full-text (484 KB) | HTML Full-text | XML Full-text
Abstract
We study the cosmic evolution of the Bianchi type I universe by using new holographic dark energy model in the context of the Brans-Dicke theory for both non-interacting and interacting cases between dark energy and dark matter. We evaluate the equation of state [...] Read more.
We study the cosmic evolution of the Bianchi type I universe by using new holographic dark energy model in the context of the Brans-Dicke theory for both non-interacting and interacting cases between dark energy and dark matter. We evaluate the equation of state for dark energy ω D and draw the ω D ω ˙ D plane, where the dot denotes the time derivative. It is found that a stage in which the cosmic expansion is accelerating can be realized in both cases. In addition, we investigate the stability of the model by analyzing the sound speed. As a result, it is demonstrated that for both cases, the behavior of the sound speed becomes unstable. Furthermore, with the Om-diagnostic tool, it is shown that the quintessence region of the universe can exist. Full article
(This article belongs to the Special Issue Cosmological Inflation, Dark Matter and Dark Energy)
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