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The mysterious relation between the large scale structure of the universe and the tiny (Planck) scale structure of the particle physics, e.g. the observed mysterious relation between the (dark) energy density (and the dark matter) of the…

High Energy Physics - Theory · Physics 2010-05-21 Kazunari Shima , Motomu Tsuda

In light of G\"{o}del's undecidability results (incomplete theorems) for math, quantum indeterminism indicates that physics and the Universe may be indeterministic, incomplete, and open in nature, and therefore demand no single unification…

General Physics · Physics 2020-03-11 Wanpeng Tan

The standard theoretical estimation of the thermal dark matter abundance may be significantly altered if properties of dark matter particles in the early universe and at the present cosmological epoch differ. This may happen if, e.g., a…

High Energy Physics - Phenomenology · Physics 2020-04-01 Archil Kobakhidze , Michael A. Schmidt , Matthew Talia

We consider the fate of future singularities in the effective dynamics of loop quantum cosmology. Non-perturbative quantum geometric effects which lead to $\rho^2$ modification of the Friedmann equation at high energies result in generic…

General Relativity and Quantum Cosmology · Physics 2008-11-26 M. Sami , Parampreet Singh , Shinji Tsujikawa

We provide an Emergent Universe picture in which the fine-tuning on the initial conditions is replaced by cut-off physics, implemented on a semiclassical level when referred to the Universe dynamics and on a purely quantum level for the…

General Relativity and Quantum Cosmology · Physics 2023-09-11 Gabriele Barca , Giovanni Montani , Alessandro Melchiorri

The establishment of extremely strong bounds on the magnitude of the electric dipole moment of the neutron, a quantity that is of great importance for determining the level of time reversal symmetry respected by the strong interactions,…

Quantum Physics · Physics 2026-02-17 Daniel Sudarsky , Octavio Guerrero

We start with the cosmic Friedmann equations, where we adopt a novel perspective rooted in a Lagrangian formulation grounded in Newtonian mechanics and the first law of thermodynamics. Our investigation operates under the assumption that…

General Relativity and Quantum Cosmology · Physics 2024-06-19 Jaume de Haro

The model of the Universe in this paper uses equations of the unperturbed Keplerian motion. They have been updated, complementied and generalized when the solution of these equations is the characteristic function of a random value from the…

General Physics · Physics 2007-11-09 Felix Hovsepian

We revise the statistical properties of the primordial cosmological density anisotropies that, at the time of matter radiation equality, seeded the gravitational development of large scale structures in the, otherwise, homogeneous and…

High Energy Physics - Phenomenology · Physics 2008-11-26 David H. Oaknin

We develop a scenario for the emergence of a non-singular generic cosmological solution based on the a WKB characterization of one of the two anisotropy degrees of freedom. We investigate the dynamics of the so-called inhomogeneous…

General Relativity and Quantum Cosmology · Physics 2021-06-16 Giovanni Montani , Roberta Chiovoloni

We consider a non singular origin for the Universe starting from an Einstein static Universe in the framework of a theory which uses two volume elements $\sqrt{-{g}}d^{4}x$ and $\Phi d^{4}x$, where $\Phi $ is a metric independent density,…

General Relativity and Quantum Cosmology · Physics 2015-05-28 E. I. Guendelman

Detailed observations of the temperature fluctuations in the microwave background radiation indicate that we live in an open universe. From the size of these fluctuations it is concluded that the geometry of the universe is quite close to…

Astrophysics · Physics 2009-11-07 Selcuk Bayin

We investigate the impact of the generalized uncertainty principle proposed by some approaches to quantum gravity such as string theory and doubly special relativity on the cosmology. Using generalized Poisson brackets, we obtain the…

General Relativity and Quantum Cosmology · Physics 2019-05-22 Mahdi Rashki , Majid Fathi , Behrang Mostaghel , Sahram Jalalzadeh

The observable universe is fundamentally inhomogeneous and anisotropic. Quantum description of the generation of these inhomogeneities and anisotropies is ill-understood and unsatisfactory. After providing a brief account of the standard…

General Relativity and Quantum Cosmology · Physics 2024-04-05 Sujoy K. Modak

Based on the entropy-area relation from Nouicer's generalised uncertainty principle (GUP), we derive the GUP modified Friedmann equations from the first law of thermodynamics at apparent horizon. We find a minimum apparent horizon due to…

General Relativity and Quantum Cosmology · Physics 2024-04-30 Özgür Ökcü

In this paper we investigate how the energy density due to a non-standard choice of initial vacuum affects the expansion of the universe during inflation. To do this we introduce source terms in the Friedmann equations making sure that we…

High Energy Physics - Theory · Physics 2014-11-18 Ulf H. Danielsson

Researches in the several decades have shown that the dynamics of gravity is closely related to thermodynamics of the horizon. In this paper, we derive the Friedmann acceleration equation based on the idea of "emergence of space" and…

General Relativity and Quantum Cosmology · Physics 2018-09-03 Fei-Quan Tu , Yi-Xin Chen , Bin Sun , You-Chang Yang

The evolution of the perturbations in the energy density and the particle number density in a flat Friedmann-Lemaitre-Robertson-Walker universe in the radiation-dominated era and in the epoch after decoupling of matter and radiation is…

General Relativity and Quantum Cosmology · Physics 2021-03-09 P. G. Miedema

The evolution with time of the abundance of galaxy clusters is very sensitive to the statistical properties of the primordial density perturbations. It can thus be used to probe small deviations from Gaussianity in the initial conditions.…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-30 A. M. M. Trindade , P. P. Avelino , P. T. P. Viana

We present a model-independent reconstruction of the early expansion and thermal histories of the universe, obtained from light element abundance measurements. The expansion history is tightly constrained around the onset of the Big Bang…

Cosmology and Nongalactic Astrophysics · Physics 2024-02-23 Rui An , Vera Gluscevic