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Related papers: Expectation values of minimum-length Ricci scalar

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Using a \emph{gedanken} experiment providing presumably a minimal inaccuracy the uncertainty contributions to the space-time measurement are precisely evaluated for clock and mirror respectively. The resulting expression of minimal…

High Energy Physics - Phenomenology · Physics 2007-05-23 Michael Maziashvili

We establish a weak compactness theorem for the moduli space of closed Ricci flows with uniformly bounded entropy, each equipped with a natural spacetime distance, under pointed Gromov-Hausdorff convergence. Furthermore, we develop a…

Differential Geometry · Mathematics 2026-04-10 Hanbing Fang , Yu Li

The Raychaudhuri equation for a geodesic congruence in the presence of a zero-point length has been investigated. This is directly related to the small-scale structure of spacetime and possibly captures some quantum gravity effects. The…

General Relativity and Quantum Cosmology · Physics 2019-09-04 Sumanta Chakraborty , Dawood Kothawala , Alessandro Pesci

The main purpose of this paper is to investigate the curvature behavior of four dimensional shrinking gradient Ricci solitons. For such soliton $M$ with bounded scalar curvature $S$, it is shown that the curvature operator $\mathrm{Rm}$ of…

Differential Geometry · Mathematics 2015-12-23 Ovidiu Munteanu , Jiaping Wang

Riemannian geometry provides us with powerful tools to explore the latent space of generative models while preserving the underlying structure of the data. The latent space can be equipped it with a Riemannian metric, pulled back from the…

Machine Learning · Computer Science 2023-10-13 Alison Pouplin , David Eklund , Carl Henrik Ek , Søren Hauberg

A critical length has recently been identified that appears to provide a fundamental limit distinguishing quantum behavior from classical behavior. Because of the unique association between critical length and mass, it appears that we can…

General Physics · Physics 2007-05-23 C. L. Herzenberg

It has been suggested that the recent acceleration of the expansion of the Universe is due a modified gravitational action consisting of the Einstein-Hilbert term plus a term proportional to the reciprocal of the Ricci scalar. Although the…

Astrophysics · Physics 2008-11-26 Eanna E. Flanagan

Ricci-flat spacetimes of signature (2,q) with q=2,3,4 are constructed which admit irreducible Killing tensors of rank-3 or rank-4. The construction relies upon the Eisenhart lift applied to Drach's two-dimensional integrable systems which…

General Relativity and Quantum Cosmology · Physics 2015-05-20 Marco Cariglia , Anton Galajinsky

Many modern theories which try to unify gravity with the Standard Model of particle physics, as e.g. string theory, propose two key modifications to the commonly known physical theories: i) the existence of additional space dimensions; ii)…

Physics Education · Physics 2012-05-07 Martin Sprenger , Piero Nicolini , Marcus Bleicher

Curvature is a fundamental geometric characteristic of smooth spaces. In recent years different notions of curvature have been developed for combinatorial discrete objects such as graphs. However, the connections between such discrete…

Probability · Mathematics 2023-11-09 Pim van der Hoorn , Gabor Lippner , Carlo Trugenberger , Dmitri Krioukov

The M-relative distance, denoted by \rho_M is a generalization of the p-relative distance, which was introduced by Ren-Cang Li. We establish necessary and sufficient conditions under which \rho_M is a metric. In two special cases we derive…

Metric Geometry · Mathematics 2007-05-23 Peter A. Hasto

The main subject of the work is experimental investigation of local-time effect existence on laboratory scale, which means longitudinal distances between locations of measurements from tens to one meter. Also short revue of our…

General Physics · Physics 2007-05-23 V. A. Panchelyuga , V. A. Kolombet , M. S. Panchelyuga , S. E. Shnoll

We show that the distance function under the Ricci flow is uniformly continuous in the time direction, assuming only the scalar curvature is bounded.

Differential Geometry · Mathematics 2017-09-05 Gang Tian , Qi S. Zhang

A complete classification of the regular representations of the relations [T,X_j] = (i/k)X_j, j=1,...,d, is given. The quantisation of RxR^d canonically (in the sense of Weyl) associated with the universal representation of the above…

Mathematical Physics · Physics 2010-04-29 Ludwik Dabrowski , Gherardo Piacitelli

We prove that a Ricci flow cannot develop a finite time singularity assuming the boundedness of a suitable space-time integral norm of the curvature tensor. Moreover, the extensibility of the flow is proved under a Ricci lower bound and the…

Differential Geometry · Mathematics 2020-01-28 Gianmichele Di Matteo

The effective quantum dynamics of Bianchi I spacetime is addressed within the statistical regularization scheme in Quantum Reduced Loop Gravity. The case of a minimally coupled massless scalar field is studied and compared with the…

General Relativity and Quantum Cosmology · Physics 2019-05-29 Emanuele Alesci , Gioele Botta , Giovanni Luzi , Gabriele V. Stagno

The main aim of this article is to investigate a spacetime of quasi-constant sectional curvature. At first, the existence of such a spacetime is established by several examples. We have shown that a spacetime of quasi-constant sectional…

Differential Geometry · Mathematics 2024-02-27 Uday Chand De , Krishnendu De , Fusun Ozen Zengin , Sezgin Altay Demirbag

In a purely relational theory there exists a tension between the relational character of the theory and the existence of quantities like distance and duration. We review this issue in the context of the Leibniz-Clarke correspondence. We…

General Relativity and Quantum Cosmology · Physics 2007-05-23 Olaf Dreyer

Quantum tunneling across double potential barriers is studied. With the assumption that the real space is a continuum, it is rigorously proved that large barriers of arbitrary shapes can be penetrated by low-energy particles with a…

Mesoscale and Nanoscale Physics · Physics 2024-02-02 Yong Yang

We apply the conformal method to solve the initial value formulation of general relativity to the $\lambda$-R model, a minimal, anisotropic modification of general relativity with a preferred foliation and two local degrees of freedom. We…

General Relativity and Quantum Cosmology · Physics 2024-06-19 Luis Pires
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