Unification of dark energy and dark matter from diffusive cosmology

Benisty, David; Guendelman, Eduardo; Haba, Z.

doi:10.1103/physrevd.99.123521

Cited by 36 publications

(21 citation statements)

References 32 publications

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“…While [94] considers one type of the stress energy momentum tensor T µν (χ) , the last paper in this thesis, [95], analyzes the complete combination of the stress energy momentum tensor with regards to diffusive interactions. Reference [95] shows analytically and numerically that all of the solutions yield the stable ΛCDM model with new families of solutions. The general consideration of T µν (χ) includes the constants λ 1 and λ 2 .…”

Section: Discussionmentioning

confidence: 99%

Dark energy and dark matter unification from dynamical space time: observational constraints and cosmological implications

Anagnostopoulos

Benisty

Basilakos

et al. 2019

J. Cosmol. Astropart. Phys.

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A recently proposed Dynamical Space-time Cosmology (DSC) that unifies dark energy and dark matter is studied. The general action of this scenario includes a Lagrange multiplier, which is coupled to the energy momentum tensor and a scalar field which is different from quintessence. First for various types of potentials we implement a critical point analysis and we find solutions which lead to cosmic acceleration and under certain conditions to stable late-time attractors. Then the DSC cosmology is confronted with the latest cosmological data from low-redshift probes, namely measurements of the Hubble parameter and standard candles (Pantheon SnIa, Quasi-stellar objects). Performing an overall likelihood analysis and using the appropriate information criteria we find that the explored DSC models are in very good agreement with the data. We also find that one of the DSC models shows a small but non-zero deviation from Λ cosmology, nevertheless the confidence level is close to ∼ 1.5σ.

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Section: Discussionmentioning

confidence: 99%

Dark energy and dark matter unification from dynamical space time: observational constraints and cosmological implications

Anagnostopoulos

Benisty

Basilakos

et al. 2019

J. Cosmol. Astropart. Phys.

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“…However, it must be stressed that, despite this characteristic, the adoption of non-covariant approaches to classical GR and quantum gravity is widespread and can be helpful in cases where the choice of a “preferred frame” may exist. Examples include numerical relativity [ 30 ], classical and quantum cosmology [ 31 , 32 , 33 , 34 , 35 ], quantum-field phenomena associated with black-hole physics [ 36 , 37 ].…”

Section: Setting the Problem In The Context Of Quantum Gravitymentioning

confidence: 99%

The Heisenberg Indeterminacy Principle in the Context of Covariant Quantum Gravity

Tessarotto

Cremaschini

2020

Entropy

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The subject of this paper deals with the mathematical formulation of the Heisenberg Indeterminacy Principle in the framework of Quantum Gravity. The starting point is the establishment of the so-called time-conjugate momentum inequalities holding for non-relativistic and relativistic Quantum Mechanics. The validity of analogous Heisenberg inequalities in quantum gravity, which must be based on strictly physically observable quantities (i.e., necessarily either 4-scalar or 4-vector in nature), is shown to require the adoption of a manifestly covariant and unitary quantum theory of the gravitational field. Based on the prescription of a suitable notion of Hilbert space scalar product, the relevant Heisenberg inequalities are established. Besides the coordinate-conjugate momentum inequalities, these include a novel proper-time-conjugate extended momentum inequality. Physical implications and the connection with the deterministic limit recovering General Relativity are investigated.

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“…Clearly, other plausible causes of the observed accelerated expansion should be explored [36,13,39,62,20,25]. Because ΛCDM is based on Einstein's general relativity (GR), one possible way is to explore cosmological models not based on GR [40,15,53,51,52,14,47,17,7,16]. However, there is a degeneracy problem between models supported by GR and models based on other metric theories, generally termed Modified Gravity (MG) theories.…”

Section: Introductionmentioning

confidence: 99%

Observational constraints on Starobinsky $f(R)$ cosmology from cosmic expansion and structure growth data

Bessa,

Campista,

Bernui

2021

Preprint

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The unknown physical nature of the Dark Energy motivates in cosmology the study of modifications of the gravity theory at large distances. One of these types of modifications are the theories known as f (R) gravity. In this paper we use observational data to both constraint and test the Starobinsky f (R) model [57], using updated measurements from the dynamics of the expansion of the universe, H(z), and the growth rate of cosmic structures, [f σ8](z), where the distinction between the concordance ΛCDM model and modified gravity models, f (R), become clearer. We use MCMC likelihood analyses to explore the parameters space of the f (R) model using H(z) and [f σ8](z) data, both individually and jointly, and further check which of the models better fit the joint data. To further test the Starobinsky model, we use a method proposed by Linder [38], where the data from the observables is jointly binned in redshift space. This allows to further explore the model's parameter that better fits the data in comparison to the ΛCDM model. Our analyses show that the result from the MCMC run using [f σ8](z) data alone fits the analyzed model better than using the joint data. At the end, we reaffirm that this joint analysis is able to break the degenerescence between modified gravity models through the f σ8 observable, as the original author proposed; our results show that the f (R) Starobinsky model although not favored by the available data, cannot be discarded and is a possible alternative to the ΛCDM model.

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Unification of dark energy and dark matter from diffusive cosmology

Cited by 36 publications

References 32 publications

Dark energy and dark matter unification from dynamical space time: observational constraints and cosmological implications

Dark energy and dark matter unification from dynamical space time: observational constraints and cosmological implications

The Heisenberg Indeterminacy Principle in the Context of Covariant Quantum Gravity

Observational constraints on Starobinsky $f(R)$ cosmology from cosmic expansion and structure growth data

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