As a part of the online conference "Geometric Foundations of Gravity 2021" there will be a public popular level lecture
on Tuesday 29 June 2021 at 6:15 p.m. (GMT+3:00) where
Professor Celia Escamilla Riviera (Instituto de Ciencias Nucleares, Universidad Nacional Autonoma de Mexico) will speak on the topic
"How a dispute over a single number became a cosmological crisis"Abstract: Toward the end of the 20th century, the cosmology seemed secure and with fertile areas for further research: the universe consisted of approximately two-thirds dark energy (a mysterious something that is accelerating the expansion of the universe), maybe a quarter dark matter (a mysterious something that determines the evolution of structure in the universe), and small percent of “ordinary” matter (the stuff of us — and of planets, stars, galaxies and everything else we had always thought)… But, not so fast with these ideas! Or, more accurately, too fast. Measurements beginning in today's universe and working backward to earlier and earlier stages have consistently revealed one value for the so-called Hubble-Lemaître constant H0 (the observation in physical cosmology that galaxies are moving away from the Earth at speeds proportional to their distance). Measurements beginning at the earliest stages of the universe and working forward, however, have consistently predicted another value — one that suggests the universe is expanding faster than we had thought. Two divergent measurements of how fast the universe is expanding cannot both be right. Something must give - but what? Let us discuss about it in this talk.
The talk can be followed online in a BigBlueButton room at
Free entry. Everybody is welcome!