English
Related papers

Related papers: Natural solution to the naturalness problem -- Uni…

200 papers

In this report, we discuss a candidate mechanism through which one might address the various cosmological constant problems. We first observe that the renormalization of gravitational couplings (induced by integrating out various matter…

High Energy Physics - Theory · Physics 2010-03-17 Subodh P. Patil

A new approach to tackle Einstein equations for an isotropic and homogeneous Friedmann--Robertson--Walker Universe in the presence of a quintessence scalar field is devised. It provides a way to get a simple exact solution to these…

General Relativity and Quantum Cosmology · Physics 2016-04-12 Felipe A. Asenjo , Sergio A. Hojman

We revise the cosmological standard model presuming that matter, i.e. baryons and cold dark matter, exhibits a non-vanishing pressure mimicking the cosmological constant effects. In particular, we propose a scalar field Lagrangian $\mathcal…

General Relativity and Quantum Cosmology · Physics 2018-11-28 Orlando Luongo , Marco Muccino

We interpret steady linear statistical inverse problems as artificial dynamic systems with white noise and introduce a stochastic differential equation (SDE) system where the inverse of the ending time $T$ naturally plays the role of the…

Numerical Analysis · Mathematics 2020-04-10 Shuai Lu , Pingping Niu , Frank Werner

We construct global-in-time singular dynamics for the (renormalized) cubic fourth order nonlinear Schr\"odinger equation on the circle, having the white noise measure as an invariant measure. For this purpose, we introduce the…

Analysis of PDEs · Mathematics 2020-11-25 Tadahiro Oh , Nikolay Tzvetkov , Yuzhao Wang

Universe evolution, as described by Friedmann's equations, is determined by source terms fixed by the choice of pressure $\times$ energy-density equations of state $p(\rho)$. The usual approach in Cosmology considers equations of state…

General Relativity and Quantum Cosmology · Physics 2008-11-26 R. Aldrovandi , R. R. Cuzinatto , L. G. Medeiros

This paper considers the optimization problem in the form of $\min_{X \in \mathcal{F}_v} f(x) + \lambda \|X\|_1,$ where $f$ is smooth, $\mathcal{F}_v = \{X \in \mathbb{R}^{n \times q} : X^T X = I_q, v \in \mathrm{span}(X)\}$, and $v$ is a…

Optimization and Control · Mathematics 2023-07-21 Wen Huang , Meng Wei , Kyle A. Gallivan , Paul Van Dooren

We consider the surface Stokes equation with Lagrange multiplier and approach it numerically. Using a Taylor-Hood surface finite element method, along with an appropriate estimate for the additional Lagrange multiplier, we derive a new…

Numerical Analysis · Mathematics 2025-07-03 Charles M. Elliott , Achilleas Mavrakis

We show that scale invariance provides a solution to the fine tuning problem of the cosmological constant. We construct a generalization of the standard model of particle physics which displays exact quantum scale invariance. The matter…

High Energy Physics - Phenomenology · Physics 2011-02-02 Pankaj Jain , Subhadip Mitra , Sukanta Panda , Naveen K. Singh

The mechanism of continuous set of different universes formation is elaborated. It provides tool to solve the problem of observed smallness of physical parameters. Solution of two puzzles - the hierarchy and the cosmological constant…

General Relativity and Quantum Cosmology · Physics 2015-11-13 Sergey G. Rubin

Recently the global variation of the Planck mass in the General Relativistic Einstein-Hilbert action was proposed as a self-tuning mechanism of the cosmological constant preventing vacuum energy from freely gravitating. We show that this…

General Relativity and Quantum Cosmology · Physics 2020-08-12 Daniel Sobral-Blanco , Lucas Lombriser

The observable universe is necessarily hospitable for life. There are indications, however, that the laws of physics and cosmological parameters need not take the form and values observed, and if they were slightly different life could not…

General Physics · Physics 2012-07-24 Colin S. Coleman

Our main aim is to apply the theory of regularly varying functions to the asymptotical analysis at infinity of solutions of Friedmann cosmological equations. A new constant $\Gamma$ is introduced related to the Friedmann cosmological…

General Relativity and Quantum Cosmology · Physics 2017-03-21 Žarko Mijajlović , Nadežda Pejović , Stevo Šegan , Goran Damljanović

An explicit retrocausal model is used to analyze the general Wood-Spekkens argument [1] that any causal explanation of Bell-inequality violations must be unnaturally fine-tuned to avoid signaling. The no-signaling aspects of the model turn…

Quantum Physics · Physics 2019-06-17 D. Almada , K. Ch'ng , S. Kintner , B. Morrison , K. B. Wharton

The spontaneous breaking of local Lorentz invariance in the early Universe, associated with a first order phase transition at a critical time $t_c$, generates a large increase in the speed of light and a superluminary communication of…

General Relativity and Quantum Cosmology · Physics 2008-11-26 J. W. Moffat

We propose an approach to explaining why naive large quantum fluctuations are not the right estimate for the cosmological constant. We argue that the universe is in a superposition of many vacua, in such a way that the resulting…

High Energy Physics - Phenomenology · Physics 2009-11-10 G. L. Kane , M. J. Perry , A. N. Zytkow

We show local and global well-posedness results for the Hartree equation $$i\partial_t\gamma=[-\Delta+w*\rho_\gamma,\gamma],$$ where $\gamma$ is a bounded self-adjoint operator on $L^2(\R^d)$, $\rho_\gamma(x)=\gamma(x,x)$ and $w$ is a…

Mathematical Physics · Physics 2015-06-17 Mathieu Lewin , Julien Sabin

Cosmological perturbation theory is an example of a gauge theory, where gauge transformations correspond to changes in the space-time coordinate system. To determine physical quantities, one is free to introduce gauge conditions (\ie to…

General Relativity and Quantum Cosmology · Physics 2025-01-23 Danilo Artigas , Julien Grain , Vincent Vennin

The dilaton-gravity sector of the Two Measures Field Theory (TMT)is explored in detail in the context of cosmology. The model possesses scale invariance which is spontaneously broken due to the intrinsic features of the TMT dynamics. The…

General Relativity and Quantum Cosmology · Physics 2008-11-26 E. I. Guendelman , A. B. Kaganovich

We explain in detail the quantum-to-classical transition for the cosmological perturbations using only the standard rules of quantum mechanics: the Schrodinger equation and Born's rule applied to a subsystem. We show that the conditioned,…

General Relativity and Quantum Cosmology · Physics 2018-09-05 Timothy J. Hollowood