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We demonstrate that, in the context of the $\Lambda$CDM model, it is in principle possible to measure the value of the cosmological constant by tracing, across cosmic time, the evolution of the turnaround radius of cosmic structures. The…

Cosmology and Nongalactic Astrophysics · Physics 2016-01-18 Dimitrios Tanoglidis , Vasiliki Pavlidou , Theodore Tomaras

The accelerating expansion of the Universe points to a small positive value for the cosmological constant or vacuum energy density. We discuss recent ideas that the cosmological constant plus LHC results might hint at critical phenomena…

High Energy Physics - Phenomenology · Physics 2015-07-09 Steven D. Bass

Possible connections between quantum entanglement and cosmological eras are considered. In particular, assuming that two epochs are each other entangled, by measuring the entanglement degree, it is possible to recover dynamical properties…

General Relativity and Quantum Cosmology · Physics 2015-06-19 S. Capozziello , O. Luongo

We analyze the basic cosmological effects of a population of timelike boundaries -- a form of nontrivial spacetime topology -- containing a boundary layer of quantum stress energy. This accumulation of vacuum fluctuations of quantum fields…

Cosmology and Nongalactic Astrophysics · Physics 2025-08-26 Oliver H. E. Philcox , Eva Silverstein , Gonzalo Torroba

A new kind of evolution for cyclic models in which the Hubble parameter oscillates and keeps positive has been explored in a specific $f(R,T)$ gravity reconstruction. A singularity-free cyclic universe with negative varying cosmological…

General Relativity and Quantum Cosmology · Physics 2019-02-11 Nasr Ahmed , Sultan Z. Alamri

Recent results indicate the presence of a cosmological constant (or related dark energy) in the universe. It has been conjectured recently that the interaction parameters of physical theories may be dependant on the size parameter of the…

Astrophysics · Physics 2007-05-23 N. Panchapakesan

This Letter investigates the formation of quantum droplets in curved spacetime, highlighting the significant influence of curvature on the formation and properties of these objects. While our computations encompass various dimensions, we…

High Energy Physics - Theory · Physics 2025-12-18 Antonino Flachi , Takahiro Tanaka

In this paper, our focus is on investigating the impact of cosmological constant on relativistic quantum systems comprising spin-0 scalar particles. Our analysis centers around the Klein-Gordon equation, and we obtain both approximate and…

General Relativity and Quantum Cosmology · Physics 2024-04-02 Faizuddin Ahmed , Abdelmalek Bouzenada

Recent observations of Type 1a supernovae indicating an accelerating universe have once more drawn attention to the possible existence, at the present epoch, of a small positive Lambda-term (cosmological constant). In this paper we review…

Astrophysics · Physics 2009-10-31 Varun Sahni , Alexei Starobinsky

We examine the general issue of whether a scale dependent cosmological constant can be consistent with general covariance, a problem that arises naturally in the treatment of quantum gravitation where coupling constants generally run as a…

High Energy Physics - Theory · Physics 2015-06-12 Herbert W. Hamber , Reiko Toriumi

We discuss from the condensed-matter point of view the recent idea that the Poisson fluctuations of cosmological constant about zero could be a source of the observed dark energy. We argue that the thermodynamic fluctuations of Lambda are…

General Relativity and Quantum Cosmology · Physics 2009-11-10 G. E. Volovik

Light scalar fields very naturally appear in modern cosmological models, affecting such parameters of Standard Model as electromagnetic fine structure constant $\alpha$, dimensionless ratios of electron or quark mass to the QCD scale,…

Atomic Physics · Physics 2009-08-18 V. V. Flambaum , E. V. Shuryak

We consider further consequences of recently [1] revealed role of cosmological constant \Lambda as of a physical constant, along with the gravitational one to define the gravity i.e. the General Relativity and its low-energy limit. We now…

General Physics · Physics 2019-03-13 V. G. Gurzadyan , A. Stepanian

We discuss the cosmological constant problem in the light of dilatation symmetry and its possible anomaly. For dilatation symmetric quantum theories realistic asymptotic cosmology is obtained provided the effective potential has a…

High Energy Physics - Theory · Physics 2017-11-13 C. Wetterich

General relativity promotes space-time to a physical, dynamical object subject to equations of motion. Quantum gravity, accordingly, must provide a quantum framework for space-time, applicable on the smallest distance scales. Just like…

General Relativity and Quantum Cosmology · Physics 2010-02-15 Martin Bojowald

I describe an approach which relates classical gravity to the quantum microstructure of spacetime. In this approach, the field equations arise from maximizing the density of states of the matter plus geometry. The former is identified using…

General Relativity and Quantum Cosmology · Physics 2017-08-22 Thanu Padmanabhan

Observations suggest that nearly seventy per cent of the energy density in the universe is unclustered and exerts negative pressure. Theoretical understanding of this component (`dark energy'), which is driving an accelerated expansion of…

Astrophysics · Physics 2007-05-23 T. Padmanabhan

Several examples are known where quantum gravity effects resolve the classical big bang singularity by a bounce. The most detailed analysis has probably occurred for loop quantum cosmology of isotropic models sourced by a free, massless…

General Relativity and Quantum Cosmology · Physics 2008-12-18 Martin Bojowald

Quantum gravity phenomenology has been historically regarded as a difficult endeavour, due to the apparent scarcity of phenomena involving the required scales of length (Planck length $l_P$) and energy (Planck energy $E_P$). It was…

High Energy Physics - Phenomenology · Physics 2023-10-10 Andrea Bevilacqua , Jerzy Kowalski-Glikman , Wojciech Wislicki

One brief idea on the extended uncertainty relation and the dynamical quantization of space-time at the Planck scale is presented. The extended uncertainty relation could be a guiding principle toward the renormalizable quantum gravity.…

General Relativity and Quantum Cosmology · Physics 2014-04-28 Choong Sun Kim