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We present three-dimensional simulations of Einstein equations implementing a symmetric hyperbolic system of equations with dynamical lapse. The numerical implementation makes use of techniques that guarantee linear numerical stability for…

General Relativity and Quantum Cosmology · Physics 2009-11-10 Manuel Tiglio , Luis Lehner , David Neilsen

The gravitationally-driven evolution of cold dark matter dominates the formation of structure in the Universe over a wide range of length scales. While the longest scales can be treated by perturbation theory, a fully quantitative…

Astrophysics · Physics 2009-11-10 Katrin Heitmann , Paul M. Ricker , Michael S. Warren , Salman Habib

We present numerical relativity simulations of cosmological scenarios in which the universe is smoothed and flattened by undergoing a phase of slow contraction and test their sensitivity to a wide range of initial conditions. Our numerical…

General Relativity and Quantum Cosmology · Physics 2020-08-14 Anna Ijjas , William G. Cook , Frans Pretorius , Paul J. Steinhardt , Elliot Y. Davies

Useful relations describing arbitrary parameters of given quantum systems can be derived from simple physical constraints imposed on the vectors in the corresponding Hilbert space. This is well known and it usually proceeds by partitioning…

Quantum Physics · Physics 2022-10-18 Chinonso Onah

New boundary conditions are constructed and tested numerically for a general first-order form of the Einstein evolution system. These conditions prevent constraint violations from entering the computational domain through timelike…

General Relativity and Quantum Cosmology · Physics 2009-11-10 Lawrence E. Kidder , Lee Lindblom , Mark A. Scheel , Luisa T. Buchman , Harald P. Pfeiffer

Waveforms of gravitational waves provide information about a variety of parameters for the binary system merging. However, standard calculations have been performed assuming a FLRW universe with no perturbations. In reality this assumption…

General Relativity and Quantum Cosmology · Physics 2019-10-10 Daniele Bertacca , Alvise Raccanelli , Nicola Bartolo , Sabino Matarrese

Accurate gravity field calculations are necessary for landing on planets, moons, asteroids, minimoons, or other irregularly shaped bodies, but current methods become increasingly inaccurate and slow near the surface. We present high…

Earth and Planetary Astrophysics · Physics 2024-11-26 Thomas MacLean , Alan H. Barr

Given a functional for a one-dimensional physical system, a classical problem is to minimize it by finding stationary solutions and then checking the positive definiteness of the second variation. Establishing the positive definiteness is,…

Classical Analysis and ODEs · Mathematics 2017-04-26 Thomas Lessinnes , Alain Goriely

We present a method for localizing a single camera with respect to a point cloud map in indoor and outdoor scenes. The problem is challenging because correspondences of local invariant features are inconsistent across the domains between…

Computer Vision and Pattern Recognition · Computer Science 2021-06-08 Peng Yin , Lingyun Xu , Ji Zhang , Howie Choset , Sebastian Scherer

We present a constructive method to devise boundary conditions for solutions of second-order elliptic equations so that these solutions satisfy specific qualitative properties such as: (i) the norm of the gradient of one solution is bounded…

Analysis of PDEs · Mathematics 2012-10-16 Guillaume Bal , Matias Courdurier

Relativistic Coulomb systems are studied in velocity space, prompted by the fact that the study of Newtonian Kepler/Coulomb systems in velocity space provides a method much simpler (and more elegant) than the familiar analytic solutions in…

Classical Physics · Physics 2017-01-31 Uri Ben-Ya'acov

The investigations presented in this study are directed at relativistic modifications of the uncertainty relation derived from the curvature of the background spacetime. These findings generalize previous work which is recovered in the…

General Relativity and Quantum Cosmology · Physics 2022-10-12 Fabian Wagner

We introduce a new type of boundary conditions, {\it smooth boundary conditions}, for numerical studies of quantum lattice systems. In a number of circumstances, these boundary conditions have substantially smaller finite-size effects than…

Condensed Matter · Physics 2009-10-22 M. Vekic , S. R. White

We give a necessary condition that a separable measurement can be implemented by local quantum operations and classical communication (LOCC) in any finite number of rounds of communication, generalizing and strengthening a result obtained…

Quantum Physics · Physics 2015-07-01 Scott M. Cohen

Applications of the three-dimensional transformation for rotating coordinate systems to quantum mechanics, general theory relativity and optics are considered.

General Physics · Physics 2019-01-08 B. V. Gisin

(highly abridged) We define three requirements for accurate simulations that attempt to model circumstellar disks and the formation of collapsed objects (e.g. planets) within them. First, we define a resolution requirement based on the…

Astrophysics · Physics 2009-11-11 Andrew F. Nelson

One of the primary challenges prohibiting demonstrations of practical quantum advantages for near-term devices amounts to excessive measurement overheads for estimating relevant physical quantities such as ground state energies. However,…

Numerical relativity is finally approaching a state where the evolution of rather general (3+1)-dimensional data sets can be computed in order to solve the Einstein equations. After a general introduction, three topics of current interest…

General Relativity and Quantum Cosmology · Physics 2017-09-27 Bernd Bruegmann

The essential matrix incorporates relative rotation and translation parameters of two calibrated cameras. The well-known algebraic characterization of essential matrices, i.e. necessary and sufficient conditions under which an arbitrary…

Computer Vision and Pattern Recognition · Computer Science 2019-12-30 E. V. Martyushev

The generalized harmonic equations of general relativity are written in 3+1 form. The result is a system of partial differential equations with first order time and second order space derivatives for the spatial metric, extrinsic curvature,…

General Relativity and Quantum Cosmology · Physics 2013-05-29 J. David Brown