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In the first part of the paper boundary-value problems are considered under weak assumptions on the smoothness of the domains. We assume nothing about smoothness of the boundary $\partial D$ of a bounded domain $D$ when the homogeneous…

Analysis of PDEs · Mathematics 2007-05-23 V. G. Goldshtein , A. G. Ramm

One of the main interest in quantum cosmology is to determine boundary conditions for the wave function of the universe which can predict observational data of our universe. For this purpose, we solve the Wheeler-DeWitt equation for a…

General Relativity and Quantum Cosmology · Physics 2017-01-23 Hiroshi Suenobu , Yasusada Nambu

Considering a generalization of the Gibbons-Hawking-York covariant boundary action that depends on both the extrinsic and the intrinsic geometry of the boundary, we derive boundary conditions for the cosmological background and tensor…

General Relativity and Quantum Cosmology · Physics 2023-05-26 David Brizuela , Marco de Cesare

In this paper, we consider a class of variational problems with integral functionals involving nonlocal gradients. These models have been recently proposed as refinements of classical hyperelasticity, aiming for an effective framework to…

Analysis of PDEs · Mathematics 2025-09-04 Carolin Kreisbeck , Hidde Schönberger

Numerical resolution of exterior Helmholtz problems requires some approach to domain truncation. As an alternative to approximate nonreflecting boundary conditions and invocation of the Dirichlet-to-Neumann map, we introduce a new, nonlocal…

Numerical Analysis · Mathematics 2021-03-04 Robert C. Kirby , Andreas Klöckner , Ben Sepanski

We compute, from first principles, the quantum fluctuations about instanton saddle points of the Euclidean path integral for Einstein gravity coupled to a scalar field. The Euclidean two-point correlator is analytically continued into the…

Astrophysics · Physics 2016-08-25 Steven Gratton , Neil Turok

For many years, the most active area of quantum cosmology has been the issue of choosing boundary conditions for the wave function of a universe. Recently, loop quantum cosmology, which is obtained from loop quantum gravity, has shed new…

General Relativity and Quantum Cosmology · Physics 2007-05-23 Martin Bojowald , Kevin Vandersloot

The boundary effects affecting the Hamiltonian for the nanocone with curvatureinduced spin orbit coupling were considered and the corresponding electronic structure was calculated. These boundary effects include the spin orbit coupling, the…

Mesoscale and Nanoscale Physics · Physics 2017-05-15 J. Smotlacha , R. Pincak

In this paper, we study the relativistic effect on the wave functions for a bouncing particle in a gravitational field. Motivated by the equivalence principle, we investigate the Klein-Gordon and Dirac equations in Rindler coordinates with…

General Relativity and Quantum Cosmology · Physics 2022-03-23 Ar Rohim , Kazushige Ueda , Kazuhiro Yamamoto , Shih-Yuin Lin

In the Einstein-Cartan framework the torsion-free conditions arise within the Hamiltonian treatment as second-class constraints. The standard strategy is to solve these constraints, eliminating the torsion from the classical theory, before…

General Relativity and Quantum Cosmology · Physics 2021-05-12 João Magueijo , Tom Zlosnik

We consider a nonlinear eigenvalue problem under Robin boundary conditions in a domain with (possibly noncompact) smooth boundary. The problem involves a weighted p-Laplacian operator and subcritical nonlinearities satisfying…

Analysis of PDEs · Mathematics 2013-05-10 Kanishka Perera , Patrizia Pucci , Csaba Varga

In this paper we study some aspects of classical and quantum cosmology in the novel-Gauss-Bonnet (nGB) gravity in four space-time dimensions. Starting with a generalised Friedmann-Lema\^itre-Robertson Walker (FLRW) metric respecting…

General Relativity and Quantum Cosmology · Physics 2020-06-04 Gaurav Narain , Hai-Qing Zhang

This article solves the initial boundary value problem for the vacuum Einstein equations with a negative cosmological constant in dimension 4, giving rise to asymptotically Anti-de Sitter spaces. We introduce a new family of geometric…

General Relativity and Quantum Cosmology · Physics 2025-07-29 Ludovic Souêtre

We consider the Hamiltonian system with Neumann boundary conditions: \[ -\Delta u + \mu u=v^{q }, \quad -\Delta v+ \mu v=u^{p} \quad \text{ in $\Omega$}, \qquad u, v >0 \quad \text{ in $\Omega$,} \qquad \partial_\nu u= \partial_\nu v=0…

Analysis of PDEs · Mathematics 2024-07-02 Angela Pistoia , Delia Schiera

Recent results of Hartle-Hawking wave functions on asymptotic dS boundaries show non-normalizability, while the bulk origin is not clear. This paper attempts to addresse this problem by studying (Kerr-)dS_3 cosmology in Einstein gravity…

High Energy Physics - Theory · Physics 2014-12-23 Lihui Liu

Recent work in the literature has proposed the use of non-local boundary conditions in Euclidean quantum gravity. The present paper studies first a more general form of such a scheme for bosonic gauge theories, by adding to the boundary…

High Energy Physics - Theory · Physics 2009-10-31 Giampiero Esposito

Condition imposed on the nonlinear terms of a nonlinear diffusion equation with {R}obin boundary condition is the main focus of this paper. The degenerate parabolic equations, such as the {S}tefan problem, the {H}ele--{S}haw problem, the…

Analysis of PDEs · Mathematics 2018-02-09 Taishi Motoda , Takeshi Fukao

In this article we are concerned with an inverse boundary value problem for a non-linear wave equation of divergence form with space dimension $n\geq 3$. In particular the so called the interior determination problem. This non-linear wave…

Analysis of PDEs · Mathematics 2019-01-15 Gen Nakamura , Manmohan Vashisth

We present a set of well-posed constraint-preserving boundary conditions for a first-order in time, second-order in space, harmonic formulation of the Einstein equations. The boundary conditions are tested using robust stability, linear and…

General Relativity and Quantum Cosmology · Physics 2008-11-26 Jennifer Seiler , Bela Szilagyi , Denis Pollney , Luciano Rezzolla

In this paper, we deal with analysis of the initial-boundary value problems for the semilinear time-fractional diffusion equations, while the case of the linear equations was considered in the first part of the present work. These equations…

Analysis of PDEs · Mathematics 2024-11-11 Yuri Luchko , Masahiro Yamamoto