Seminar “Modern Mathematical Physics”

Date and Time: Tuesday, 9 October 2018, at 2:30 PM

Venue: Blokhintsev Hall (4th floor), Bogoliubov Laboratory of Theoretical Physics

Seminar topic: «50 years of black hole concept: the Galactic Center case»

Speaker: Alexander F. Zakharov (ITEP and BLTP)

Abstract:

The black hole concept has been introduced by J. A. Wheeler in 1967 and the corresponding paper was published in 1968. We illustrate an efficiency of the idea for theoretical and observational studies of our Galactic Center. Now there are two basic observational techniques to investigate a gravitational potential at the Galactic Center to prove a presence of a supermassive black hole, namely, (a) monitoring the orbits of bright stars near the Galactic Center with the largest telescopes; (b) measuring the size and shape of shadows around black hole giving an alternative possibility to evaluate black hole parameters with the Event Horizon Telescope. Recently, the joint LIGO – Virgo team not only discovered gravitational waves and binary black holes but also found an upper limit on graviton mass m g < 1.2 x 10^-22 eV (Abbott et al. 2016). We show that an analysis of bright star trajectories could constrain graviton mass with a comparable accuracy. We discuss opportunities to improve current estimates of graviton mass significantly with subsequent observations of Keck, VLT, GRAVITY, E-ELT and TMT. We discuss recent GRAVITY results about gravitational redshift for S2 star near the pericenter passage. These results confirmed GR predictions for the Galactic Center.

BLTP Online