Gravitational waves and Hubble tension problem from a new cosmological model with variable time scale

BELLINI MAURICIO; JUAN IGNACIO MUSMARRA; ANABITARTE MARIANO; P. A. SANCHEZ

EUROPEAN PHYSICAL JOURNAL C - PARTICLES AND FIELDS

SPRINGER

Lugar: Berlin; Año: 2022

1434-6044

During preinflation, the Hubble parameter increases from an initial null value and the expansionof the universe is produced by the effect of back-reaction effects. This fact is viewed in the globaldynamics as a cosmological parameter which induces the initial expansion in a non-conservativeGeneral Relativity theory. In this work we explore a model for the universe in which preinflation isfollowed by a warming epoch that is followed by a accelerating expansion produced by dark energy,by using a previously introduced metric with variable time scale. It is shown that gravitationalwaves (GW) produced at the birth of the universe are an unique signature of such event, which aresuppressed a few Planckian times after this moment. However, the trace of GW, which are moresignificative on largest scales, decreases later but remains stable during the epoch of inflation, afterthe warming of the universe. We show that the variable time scale in the universe could be theorigin of the Hubble tension problem in cosmological observations.