arXiv subjects

Everardo Rivera-Oliva

Publications and source records attributed to Everardo Rivera-Oliva.

4 recordsLinked to original sources

arXiv2026

Kerr-Schild solutions in Multigravity and the Classical Double Copy

We explore the multimetric theory of gravitation, also known as multigravity. We derive additional new exact solutions for the theory in proportional Kerr-Schild and double Kerr-Schild forms. We extend several solutions from the theory of General Relativity, characterized by a constant Ricci scalar in single and double Kerr-Schild forms, to derive solutions in the multi-gravity context. We also examine and extend the classical double copy relations that can be constructed out from these solutions in multigravity exploring the dynamics of the single copy and zero copy fields.

gr-qc↗

arXiv2025

Another formula for calculating Clebsch Gordan coefficients

This article presents the derivation of a comprehensive formula for the Clebsch-Gordan coefficients in a quantum system. The formula is derived by employing the iterative application of angular momentum ladder operators on each defined angular momentum subspace to reconstruct the states in the total angular momentum base. The novelty aspect of this approach lies in the utilization of the $J{+}$ raising operator to reconstruct subspaces characterized by non-maximal total angular momentum, in contrast to the conventional Gram-Schmidt procedure typically employed in the standard literature.This enables us to derive a new formula that provides an alternative approach for computing these coefficients, complementing the existing ones found in the literature.

quant-ph↗

arXiv2025

Solving Linear Differential Equations by recursion and integrating factors

In this study, a recursive solution technique in conjunction with generalized integrating factors is presented and applied to address first and second order linear differential equations. This approach demonstrates practical utility in classical differential equations encountered in physics, inclusive of equations with variable coefficients, particularly when a pattern within the recursion is identifiable, thus enabling the derivation of an explicit expression for $y(x)$.

math-ph↗

arXiv2025

Solving the Riccati Equation

In this study, the Riccati equation is resolved using the generalized recursive integrating factor method. By applying a non-linear transformation to the dependent variable $y(x)$ of the Riccati equation, a second-order linear differential equation is derived for a variable $u(x)$ that is related to $y(x)$ through the aforementioned transformation. The second-order differential equation is then addressed using the aforementioned integrating factors method to derive the general solution for $u(x)$, which is subsequently transformed back to obtain the general solution for $y(x)$, thereby resolving the Riccati equation. The general solution to the Riccati equation is presented, followed by solving a few illustrative application examples.

math-ph↗