English
Related papers

Related papers: A Computer Program for the Newman-Janis Algorithm

200 papers

Computer algebra programs are presented for application in general relativity, in electrodynamics, and in gauge theories of gravity. The mathematical formalism used is the calculus of exterior differential forms, the computer algebra system…

General Relativity and Quantum Cosmology · Physics 2009-10-31 Jose Socorro , Alfredo Macias , Friedrich W. Hehl

We report the discovery of rotating black hole solutions within the framework of de Rham-Gabadadze-Tolley (dRGT) massive gravity. We demonstrate that any nonunitary gauge with the Minkowski reference metric are equal to a unitary gauge with…

General Relativity and Quantum Cosmology · Physics 2025-01-23 Ping Li , Jiang-he Yang

We propose a stochastic variance-reduced cubic regularized Newton method for non-convex optimization. At the core of our algorithm is a novel semi-stochastic gradient along with a semi-stochastic Hessian, which are specifically designed for…

Machine Learning · Computer Science 2018-02-14 Dongruo Zhou , Pan Xu , Quanquan Gu

We show that the $f(R)$-gravity theories with constant Ricci scalar in the Jordan/Einstein frame can be described by Einstein or Einstein-Maxwell gravity with a cosmological term and a modified gravitational constant. We also propose a…

General Relativity and Quantum Cosmology · Physics 2023-10-10 Pankaj Chaturvedi , Utkarsh Kumar , Udaykrishna Thattarampilly , Vishnu Kakkat

The formation of spacetime singularities is a quite common phenomenon in General Relativity and it is regulated by specific theorems. It is widely believed that spacetime singularities do not exist in Nature, but that they represent a…

General Relativity and Quantum Cosmology · Physics 2013-04-08 Cosimo Bambi , Leonardo Modesto

To date, a mathematically consistent construction of effective rotating black hole models in the context of Loop Quantum Gravity (LQG) is still lacking. In this work, we start with the assumption that rotating LQG black hole metrics can be…

General Relativity and Quantum Cosmology · Physics 2022-10-05 Che-Yu Chen

Spherical reduction of generic four-dimensional theories is revisited. Three different notions of "spherical symmetry" are defined. The following sectors are investigated: Einstein-Cartan theory, spinors, (non-)abelian gauge fields and…

General Relativity and Quantum Cosmology · Physics 2010-11-19 Herbert Balasin , Christian G. Boehmer , Daniel Grumiller

We demonstrate that the generic charged rotating regular black hole solutions of general relativity coupled to non-linear electrodynamics, obtained by using the alternate Newman-Janis algorithm, introduces only small (on level $10^{-2}$)…

General Relativity and Quantum Cosmology · Physics 2023-11-10 Bobir Toshmatov , Zdeněk Stuchlík , Bobomurat Ahmedov

A hypothetical equation of motion is proposed for Kerr-Newman particles. It is obtained by analytic continuation of the Lorentz-Dirac equation into complex space-time. A new class of "runaway" solutions are found which are similar to…

General Relativity and Quantum Cosmology · Physics 2016-06-15 Mark Davidson

The snags in Nucci(1996)REDUCE algorithm are the intrinsic computational efforts and the ability to recognize the ignorable variable(s) during the reduction process of the algorithm. An inappropriate choice of the ignorable variable(s)may…

Dynamical Systems · Mathematics 2008-06-17 Festus Irimisose Arunaye

Using on-shell amplitude methods, we derive a rotating black hole solution in a generic theory of Einstein gravity with additional terms cubic in the Riemann tensor. We give an explicit expression for the metric in Einsteinian Cubic Gravity…

High Energy Physics - Theory · Physics 2021-03-25 Daniel J. Burger , William T. Emond , Nathan Moynihan

Utilizing the Lehmann-Symanzik-Zimmermann reduction formula, we present a new general framework for computing scattering amplitudes in quantum field theory with quantum computers in a fully nonperturbative way. In this framework, one only…

High Energy Physics - Phenomenology · Physics 2024-02-28 Tianyin Li , Wai Kin Lai , Enke Wang , Hongxi Xing

The Neumann--Neumann method is a commonly employed domain decomposition method for linear elliptic equations. However, the method exhibits slow convergence when applied to semilinear equations and does not seem to converge at all for…

Numerical Analysis · Mathematics 2023-12-19 Emil Engström , Eskil Hansen

With the help of Newman-Janis method new spinning black hole (BH) solution for a non-local gravity model was obtained. We show how to account the quantum gravitational correction part in BH shadows modelling using spinning BH metrics with a…

General Relativity and Quantum Cosmology · Physics 2024-04-26 Stanislav Alexeyev , Artem Baiderin , Alexandra Nemtinova , Oleg Zenin

We show that the von Neumann's algorithm of reduction (i.e. the algorithm of calculating the density matrix of the observable subsystem from the density matrix of the closed quantum system) corresponds to the special approximation at which…

Quantum Physics · Physics 2007-05-23 N. K. Solovarov

An algorithm for solving smooth nonconvex optimization problems is proposed that, in the worst-case, takes $\mathcal{O}(\epsilon^{-3/2})$ iterations to drive the norm of the gradient of the objective function below a prescribed positive…

Optimization and Control · Mathematics 2018-03-16 Frank E. Curtis , Daniel P. Robinson , Mohammadreza Samadi

We present a simple approach for obtaining Kerr interior solutions with the help of the Newman-Janis algorithm (NJA) starting with static space-times describing physically sensible interior Schwarzschild solutions. In this context, the…

General Relativity and Quantum Cosmology · Physics 2010-11-11 Stefano Viaggiu

In [arXiv:1906.10100], the authors argued that the Newman-Janis algorithm on the space of classical solutions in general relativity and electromagnetism could be used in the space of scattering amplitudes to map an amplitude with external…

High Energy Physics - Theory · Physics 2024-05-17 Samim Akhtar , Arkajyoti Manna , Akavoor Manu

The numerical solution of the algebraic Riccati equation is a challenging task especially for very large problem dimensions. In this paper we present a new algorithm that combines the very appealing computational features of projection…

Numerical Analysis · Mathematics 2019-11-27 Davide Palitta

We propose a general random subspace framework for unconstrained nonconvex optimization problems that requires a weak probabilistic assumption on the subspace gradient, which we show to be satisfied by various random matrix ensembles, such…

Optimization and Control · Mathematics 2022-11-21 Coralia Cartis , Jaroslav Fowkes , Zhen Shao