Lucas Lombriser
University of Geneva

Abstract
I will first discuss how recent gravitational wave measurements have brought the predicted challenges to explaining cosmic acceleration by a modification of General Relativity as alternative to the cosmological constant. In a second part, I will describe a possible solution of the cosmological constant problem. I will show how interpreting the Planck mass in the Einstein-Hilbert action as a global Lagrange multiplier prevents vacuum energy from gravitating and with account of the inhomogeneous cosmic small-scale structure predicts an energy density parameter of the cosmological constant of 0.704, in good agreement with observations. Finally, I will argue that there is no Hubble tension. Rather, the discrepant measurements imply that we are located in a 50% underdense 40 Mpc region of the Cosmos, within cosmic variance and in good agreement with the measured local distributions of galaxies and clusters.

2019 December 04, 14:00

IA/U.Lisboa
Faculdade de Ciências da Universidade de Lisboa (C8.2.02)
Campo Grande, 1749-016 Lisboa