scholarly journals Nonstandard Approach to Gravity for the Dark Sector of the Universe

Entropy ◽  
2013 ◽  
Vol 15 (2) ◽  
pp. 559-605 ◽  
Author(s):  
Peter Stichel ◽  
Wojtek Zakrzewski
Keyword(s):  
Dark Sector ◽  
Nonstandard Approach ◽  
The Universe

scholarly journals A dark clue to seesaw and leptogenesis in a pseudo-Dirac singlet doublet scenario with (non)standard cosmology

2021 ◽  
Vol 2021 (3) ◽  
Author(s):  
Partha Konar ◽  
Ananya Mukherjee ◽  
Abhijit Kumar Saha ◽  
Sudipta Show
Keyword(s):  
Dark Matter ◽  
Thermal History ◽  
Direct Detection ◽  
Critical Role ◽  
Mass Term ◽  
Baryon Asymmetry ◽  
Dark Sector ◽  
Lepton Asymmetry ◽  
History Of ◽  
The Universe

Abstract We propose an appealing alternative scenario of leptogenesis assisted by dark sector which leads to the baryon asymmetry of the Universe satisfying all theoretical and experimental constraints. The dark sector carries a non minimal set up of singlet doublet fermionic dark matter extended with copies of a real singlet scalar field. A small Majorana mass term for the singlet dark fermion, in addition to the typical Dirac term, provides the more favourable dark matter of pseudo-Dirac type, capable of escaping the direct search. Such a construction also offers a formidable scope to radiative generation of active neutrino masses. In the presence of a (non)standard thermal history of the Universe, we perform the detailed dark matter phenomenology adopting the suitable benchmark scenarios, consistent with direct detection and neutrino oscillations data. Besides, we have demonstrated that the singlet scalars can go through CP-violating out of equilibrium decay, producing an ample amount of lepton asymmetry. Such an asymmetry then gets converted into the observed baryon asymmetry of the Universe through the non-perturbative sphaleron processes owing to the presence of the alternative cosmological background considered here. Unconventional thermal history of the Universe can thus aspire to lend a critical role both in the context of dark matter as well as in realizing baryogenesis.

scholarly journals Standard sirens and dark sector with Gaussian process

2018 ◽  
Vol 168 ◽  
pp. 01008 ◽  
Author(s):  
Rong-Gen Cai ◽  
Tao Yang
Keyword(s):  
Monte Carlo ◽  
Gaussian Process ◽  
Gravitational Waves ◽  
Binary Systems ◽  
Cosmological Parameters ◽  
Dark Sector ◽  
Compact Binary ◽  
Compact Binary Systems ◽  
Process Methodology ◽  
The Universe

The gravitational waves from compact binary systems are viewed as a standard siren to probe the evolution of the universe. This paper summarizes the potential and ability to use the gravitational waves to constrain the cosmological parameters and the dark sector interaction in the Gaussian process methodology. After briefly introducing the method to reconstruct the dark sector interaction by the Gaussian process, the concept of standard sirens and the analysis of reconstructing the dark sector interaction with LISA are outlined. Furthermore, we estimate the constraint ability of the gravitational waves on cosmological parameters with ET. The numerical methods we use are Gaussian process and the Markov-Chain Monte-Carlo. Finally, we also forecast the improvements of the abilities to constrain the cosmological parameters with ET and LISA combined with the Planck.

A new pressure-parametric cosmological model

2020 ◽  
Vol 35 (25) ◽  
pp. 2050209
Author(s):  
Yan-Hong Yao ◽  
Xin-He Meng
Keyword(s):  
Scalar Fields ◽  
Model Parameters ◽  
Acoustic Oscillations ◽  
Dark Sector ◽  
Type Ia ◽  
Phantom Scalar ◽  
Acceleration Of The Universe ◽  
Expansion Of The Universe ◽  
Ia Supernovae ◽  
The Universe

We put forward a pressure-parametric model to study the tiny deviation from cosmological constant(CC) behavior of the dark sector accelerating the expansion of the Universe. Data from cosmic microwave background (CMB) anisotropies, baryonic acoustic oscillations (BAO), Type Ia supernovae (SN Ia) observation are applied to constrict the model parameters. The constraint results show that such model suffers with [Formula: see text] tension as well. To realize this model more physically, we reconstruct it with the quintessence and phantom scalar fields, and find out that although the model predicts a quintessence-induced acceleration of the Universe at past and present, at some moment of the future, dark energy’s density have a disposition to increase.

scholarly journals The dark sector cosmology

2020 ◽  
Vol 29 (14) ◽  
pp. 2030014
Author(s):  
Elcio Abdalla ◽  
Alessandro Marins
Keyword(s):  
Dark Energy ◽  
Cosmological Parameters ◽  
Hubble Constant ◽  
Acoustic Oscillations ◽  
Dark Sector ◽  
Fundamental Physics ◽  
Observational Techniques ◽  
Distance Indicators ◽  
The Universe ◽  
Theoretical Developments

The most important problem in fundamental physics is the description of the contents of the Universe. Today, we know that 95% thereof is totally unknown. Two thirds of that amount is the mysterious Dark Energy described in an interesting and important review [E. J. Copeland, M. Sami and S. Tsujikawa, Int. J. Mod. Phys. D 15 (2006) 1753]. We briefly extend here the ideas contained in that review including the more general Dark Sector, that is, Dark Matter and Dark Energy, eventually composing a new physical Sector. Understanding the Dark Sector with precision is paramount for us to be able to understand all the other cosmological parameters comprehensively as modifications of the modeling could lead to potential biases of inferred parameters of the model, such as measurements of the Hubble constant and distance indicators such as the Baryon Acoustic Oscillations. We discuss several modern methods of observation that can disentangle the different possible descriptions of the Dark Sector. The possible applications of some theoretical developments are also included in this paper as well as a more thorough evaluation of new observational techniques at lower frequencies and gravitational waves.

scholarly journals Interactions in the dark sector of the Universe

2014 ◽  
Vol 11 (02) ◽  
pp. 1460014 ◽  
Author(s):  
Winfried Zimdahl
Keyword(s):  
Dark Matter ◽  
Dark Energy ◽  
Dark Sector ◽  
Future Evolution ◽  
Evolution Of The Universe ◽  
Λcdm Model ◽  
The Future ◽  
The Universe

Interactions inside the cosmological dark sector influence the cosmological dynamics. As a consequence, the future evolution of the Universe may be different from that predicted by the ΛCDM model. We review main features of several recently studied models with nongravitational couplings between dark matter and dark energy.

scholarly journals The Λ and the CDM as Integration Constants

Symmetry ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 2076
Author(s):  
Priidik Gallagher ◽  
Tomi Koivisto
Keyword(s):  
Dark Matter ◽  
Gauge Theory ◽  
Symmetry Breaking ◽  
Cosmological Constant ◽  
Spontaneous Symmetry Breaking ◽  
First Principles ◽  
Cold Dark Matter ◽  
Dark Sector ◽  
Λcdm Model ◽  
The Universe

Notoriously, the two main problems of the standard ΛCDM model of cosmology are the cosmological constant Λ and the cold dark matter, CDM. This essay shows that both the Λ and the CDM arise as integration constants in a careful derivation of Einstein’s equations from first principles in a Lorentz gauge theory. The dark sector of the universe might only reflect the geometry of a spontaneous symmetry breaking that is necessary for the existence of spacetime and an observer therein.

scholarly journals Dark sector interactions and the curvature of the universe in light of Planck's 2018 data

2021 ◽  
Vol 2021 (08) ◽  
pp. 014
Author(s):  
M. Benetti ◽  
H.A. Borges ◽  
C. Pigozzo ◽  
S. Carneiro ◽  
J.S. Alcaniz
Keyword(s):  
Dark Sector ◽  
The Universe

scholarly journals Phantom energy-dominated universe as a transient stage in f(R) cosmology

2019 ◽  
Vol 28 (10) ◽  
pp. 1950124 ◽  
Author(s):  
P. H. R. S. Moraes ◽  
P. K. Sahoo ◽  
Barkha Taori ◽  
Parbati Sahoo
Keyword(s):  
Quantum Cosmology ◽  
Bianchi Type ◽  
Phantom Energy ◽  
Type I ◽  
Dark Sector ◽  
Transient Stage ◽  
Standard Cosmology ◽  
Theories Of Gravity ◽  
The Universe ◽  
Einstein’S General Relativity

The [Formula: see text] theories of gravity are the most popular, simple and well-succeeded extension of Einstein’s General Relativity. They can account for some observational issues of standard cosmology with no need for evoking the dark sector of the universe. In the present paper, we will investigate LRS Bianchi type-I spacetime in [Formula: see text] gravity theory within the phantom energy-dominated era. We show that in this formalism the phantom energy-dominated universe is a transient stage and in the further stage of the universe dynamics, it is dominated, once again, by dark energy. Such an important feature is obtained from the model, rather than imposed to it, and may have a relation to loop quantum cosmology.

scholarly journals Non-minimal dark matter search in dark matter colliders

2018 ◽  
Vol 168 ◽  
pp. 06008
Author(s):  
Seodong Shin
Keyword(s):  
Dark Matter ◽  
Dark Sector ◽  
Fixed Target ◽  
Dark Matter Search ◽  
Fixed Target Experiments ◽  
Neutrino Scattering ◽  
Secondary Procedure ◽  
Neutrino Detectors ◽  
Detection Strategy ◽  
The Universe

In the scenarios of dark matter (DM) with a non-minimal dark sector, we revisit a new detection strategy of observing two or three simultaneous signals from inelastic scattering of a boosted DM [1]. The relativistically incoming DM can scatter off inelastically to a heavier unstable dark sector particle which decays back in to the DM associated with visible Standard Model particles inside large volume neutrino detectors. The existence of the secondary procedure renders us to separate it from conventional neutrino scattering background. The relativistically incoming DM can come from the universe by the annihilation of heavy DM component in an inelastic boosted DM scenario or produced by the beam bombardments in fixed target experiments.

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