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We briefly report on a previously found new, approximate, solution to Einstein field equations, describing a cubic lattice of spherical masses. This model mimics in a satisfactory way a Universe which can be strongly inhomogeneous at small…

General Relativity and Quantum Cosmology · Physics 2013-03-04 Jean-Philippe Bruneton

We show that the quantum wavefunctional can be seen as a set of classical fields on the 3D space aggregated by a measure. We obtain a complete description of the wavefunctional in terms of classical local beables. With this correspondence,…

Quantum Physics · Physics 2023-06-28 Ovidiu Cristinel Stoica

We specify the semiclassical no-boundary wave function of the universe without relying on a functional integral of any kind. The wave function is given as a sum of specific saddle points of the dynamical theory that satisfy conditions of…

High Energy Physics - Theory · Physics 2019-02-27 Jonathan J. Halliwell , James B. Hartle , Thomas Hertog

When the semi-positive cosmological constant is dynamical, the naive Euclidean Einstein action is unbounded from below and the Hartle-Hawking wavefunction of the universe is not normalizable. With the inclusion of back-reaction (a crucial…

High Energy Physics - Theory · Physics 2007-05-23 Saswat Sarangi , S. -H. Henry Tye

The concepts of Lorentz invariance of local (flat space) physics, and unitarity of time evolution and the S-matrix, are famously rigid and robust, admitting no obvious consistent theoretical deformations, and confirmed to incredible…

High Energy Physics - Theory · Physics 2018-11-06 Nima Arkani-Hamed , Paolo Benincasa

A tetrad-based procedure is presented for solving Einstein's field equations for spherically-symmetric systems; this approach was first discussed by Lasenby et al. in the language of geometric algebra. The method is used to derive metrics…

General Relativity and Quantum Cosmology · Physics 2015-05-27 Roshina Nandra , Anthony N. Lasenby , Michael P. Hobson

We consider the Hartle-Hawking wavefunction of the universe defined as a Euclidean path integral that satisfies the "no-boundary proposal." We focus on the simplest minisuperspace model that comprises a single scale factor degree of freedom…

High Energy Physics - Theory · Physics 2021-11-17 Hervé Partouche , Nicolaos Toumbas , Balthazar de Vaulchier

We provide an informal discussion of pattern formation in a finite universe. The global size and shape of the universe is revealed in the pattern of hot and cold spots in the cosmic microwave background. Topological pattern formation can be…

Astrophysics · Physics 2007-05-23 Janna Levin , Imogen Heard

This paper focuses on a constructive treatment of the mathematical formalism of quantum theory and a possible role of constructivist philosophy in resolving the foundational problems of quantum mechanics, particularly, the controversy over…

Quantum Physics · Physics 2016-05-25 Arkady Bolotin

Following DeMeyer, Ford & Miranda [DFM93], we define a topology on a fan by declaring open sets to be its subfans. Then, like Kato [Kat94], we make our fans into monoided spaces by associating a sheaf of monoids to each fan. (Our sheaf of…

Algebraic Geometry · Mathematics 2007-05-23 Howard M Thompson

From any graph $G$ arises a flat space wavefunction, obtained by integrating a product of propagators associated to the vertices and edges of $G$. This function is a key ingredient in the computation of cosmological correlators, and several…

Mathematical Physics · Physics 2026-03-09 Tyler Dunaisky

Set theory brought revolution to philosophy of mathematics and it can bring revolution to philosophy of physics too. All that stands in the way is the intuition that sets of physical objects cannot themselves be physical objects, which…

Quantum Physics · Physics 2023-11-29 Paul Tappenden

Energy states of the universe is obtained when the scale factor is defined as a=At^n, and n varies as -1<=n<=1,with the aid of the wavefunction which was constructed in, Mahgoub Salih, A Canonical Quantization formalism of curvature squared…

General Physics · Physics 2009-09-30 Mahgoub Salih

We investigate spectral functions in the vicinity of the critical temperature of a second-order phase transition. Since critical phenomena in quantum field theories are governed by classical dynamics, universal properties can be computed…

High Energy Physics - Lattice · Physics 2011-03-28 J. Berges , S. Schlichting , D. Sexty

When a physicist says that a theory is fine-tuned, they mean that it must make a suspiciously precise assumption in order to explain a certain observation. This is evidence that the theory is deficient or incomplete. One particular case of…

History and Philosophy of Physics · Physics 2021-10-18 Luke A. Barnes

We define and study the cyclic Bergman fan of a matroid M, which is a simplicial polyhedral fan supported on the tropical linear space T(M) of M and is amenable to computational purposes. It slightly refines the nested set structure on…

Combinatorics · Mathematics 2013-03-07 Felipe Rincón

We study closed universes in holographic theories of quantum gravity. We argue that within any fixed theory, factorization implies there is one unique closed universe state. The wave function of any state that can be prepared by the path…

High Energy Physics - Theory · Physics 2025-02-17 Mykhaylo Usatyuk , Ying Zhao

We explore observables in a lattice Universe described by a recently found solution to Einstein field equations. This solution models a regular lattice of evenly distributed objects of equal masses. This inhomogeneous solution is…

General Relativity and Quantum Cosmology · Physics 2015-06-11 Jean-Philippe Bruneton , Julien Larena

A version of the quantum theory of gravity based on the concept of the wave functional of the universe is proposed. To determine the physical wave functional, the quantum principle of least action is formulated as a secular equation for the…

General Relativity and Quantum Cosmology · Physics 2021-10-19 Natalia Gorobey , Alexander Lukyanenko , A. V. Goltsev

We investigate the meaning of the wave function by analyzing the mass and charge density distributions of a quantum system. According to protective measurement, a charged quantum system has mass and charge density distributing in space,…

General Physics · Physics 2011-07-19 Shan Gao