5 papers
Peculiar velocity fields from analytic solutions of General Relativity
Roberto A. Sussman, Sebastián Nájera, Fernando A. Pizaña +1
Peculiar velocities are analyzed through cosmological perturbations in the Newtonian longitudinal gauge characterized by irrotational shear-free congruences in an Eulerian frame. W…
Revisiting the gravitational "arrow of time"
Roberto A. Sussman, Sebastián Nájera, Fernando A. Pizaña +1
We address a long-standing misperception on the gravitational ``arrow of time'', a proposal by Penrose (also known as the ``Weyl-curvature hypothesis") that associates structure fo…
Gravitational entropy of fluids with energy flux
Roberto A. Sussman, Sebastián Nájera, Fernando A. Pizaña +1
We examine gravitational entropy growth within the formalism of Clifton, Ellis and Tavakol (CET) applied to a class of spherically symmetric exact solutions whose source is a shear…
Growth rate of spherical voids with non-comoving Dark Matter and Baryons
Fernando A. Pizaña, Juan Carlos Hidalgo, Ismael Delgado Gaspar +1
We present numerical solutions to Einstein's equations describing large spherical cosmic voids constituted by two components; dark matter and baryons, with a non-vanishing initial…
Gravitational Entropy in Szekeres Class I Models
Fernando A. Pizaña, Roberto A. Sussman, Juan Carlos Hidalgo
Gravitational entropy is an elusive concept. Various theoretical proposals have been presented, initially based on Penrose's Weyl Curvature Hypothesis, and variations of it. A more…