This is a multi-institutional online joint seminar series, named after the famous Polish Nicolaus Copernicus whose discovery eventually marked the dawn of modern science. We invite the most outstanding speakers to introduce innovative ideas and important progress in the field of gravity and cosmology.
We would like to invite you to take part in the upcoming 28th & 29th Webinar talks,
the 28th talk by Komatsu:
speaker: Eiichiro Komatsu (Max-Planck-Institute for Astrophysics)
Time: 26th January, Tuesday, 2 pm, Krakow time (9 pm Beijing time, 10 pm JST, 8am ET)
Hunting for Parity-violating Physics in Polarisation of the Cosmic Microwave Background
Polarised light of the cosmic microwave background, the remnant light of the Big Bang, is sensitive to parity-violating physics. In this presentation we report on a new measurement of parity violation from polarisation data of the European Space Agency (ESA)’s Planck satellite. The statistical significance of the measured signal is 2.4 sigma. If confirmed with higher statistical significance in future, it would have important implications for the elusive nature of dark matter and dark energy.
the 29th talk by Rubakov (2-hour talk):
speaker: Valery Rubakov (INR Moscow)
Time: 28th January, Thursday, 11 am, Krakow time (6 pm Beijing time, 7 pm JST, 5 am ET)
Title and abstract:
Cosmological Genesis: Approaches and Problems.
Cosmological Genesis is a scenario without initial singularity,
in which the Universe starts off
from nearly Minkowski state with nearly vanishing energy density,
then the energy density increases, the expansion rate grows;
at some later epoch the energy density is converted into heat,
and the conventional hot epoch begins (variant: at some later epoch
energy density stops increasing and inflationary epoch begins).
Clearly, this scenario requires exotic form of matter, which violates
energy conditions, and/or exotic modification of gravity.
This talk will concentrate on scalar-tensor theories of Horndeski type,
and generalizations thereof. Despie initial high expectations, there
are problems with stable and subluminal Genesis in these theories.
These problems, and attempts to solve them, will be the main focus.
Announcement: 1st Copernicus Colloquium
Speaker: Vlatko Vedral (Oxford University)
Time: 2nd February, 3 pm CET (2pm UK time, 10 pm Beijing time, 11pm JST, 9 am ET).
TITLE: Are there any fundamental problems with quantum gravity?
Abstract: I plan to informally discuss several issues that have traditionally been raised in various approaches to quantizing gravity. They are invariably related to the concepts that are thought to be fundamental in one of the two theories (quantum and GR) but are (allegedly) at odds with the other one. I will discuss some of the key issues in my talk, such as Bell non-locality and the equivalence principle, only to conclude that they are, in my view, not fundamentally an obstacle. Lack of experiments, on the other hand, is a real obstacle, but, even here, we are closer than ever to being able to test the quantum nature of gravity in the lab. I will describe how.