The 2019 Dirac Medal and Prize Ceremony which was due to take place in May 2020 during the ICTP Summer School on Cosmology 2020 has been re-scheduled to Friday 29 January 2021 starting at 13.30 hrs and will be online. ICTP awarded its 2019 Dirac Medal and Prize to three physicists whose research has made a profound impact on modern cosmology. Viatcheslav Mukhanov (Ludwig Maximilian University of Munich), Alexei Starobinsky (Landau Institute for Theoretical Physics) and Rashid Sunyaev (Max Planck Institute for Astrophysics, and Space Research Institute, Moscow) share the prize for “their outstanding contributions to the physics of the Cosmic Microwave Background (CMB) with experimentally tested implications that have helped to transform cosmology into a precision scientific discipline by combining microscopic physics with the large scale structure of the Universe.” All three winners have made important contributions to the understanding of the early Universe in the context of inflationary cosmology. Dirac Medal lectures (25 mins each) are as follows: * "How predictive are cosmological theories?" by Professor Viatcheslav Mukhanov. Abstract: I will discuss the robust model independent predictions of the theory of quantum origin of the universe structure and confront them with the results of the recent measurements of the CMB fluctuations. * "Beginning the Universe from the maximally symmetric state in the past" by Professor Alexei A. Starobinsky. Abstract: The radical hypothesis that our Universe was in the maximally symmetric state during some period in its remote past, as much symmetric with respect to both quasi-classical background and small quantum perturbations upon it as physical laws permit this, has been realized in some rather narrow class of slow-roll inflationary models and has led to quantitative predictions about the power spectra of primordial scalar and tensor inhomogeneous perturbations which have been confirmed by observations in the former case. From the theoretical point of view, these models provided us with the wonderful possibility to apply the previously developed quantum field theory in curved space-time, more concretely, the quantum-gravitational effect of creation of particles and field fluctuations in cosmological backgrounds, to phenomena observable at the present time. The simplest viable inflationary models which I shall discuss have only one adjustable dimensionless parameter to be taken from observations. They correctly predicted deviation of the primordial scalar spectrum from the exactly scale-invariant one (n_s =1), where n_s is the spectral slope, by relating this small quantity to the ratio of the Hubble constant to the present CMB temperature. Their next most important target prediction is about the purely quantum-gravitational effect: the amplitude of primordial tensor perturbations (gravitational waves) in terms of the relation between the tensor-to-scalar ratio r and n_s: r = 3(1- n_s)^2. However, nature may require more parameters for the phenomenological description of the inflationary stage, in particular, if some of already discovered black holes would be proven to be primordial. * "The X-Ray map of the Universe with a million accreting supermassive black holes and tens of thousands of clusters of galaxies" by Professor Rashid Sunyaev. Abstract: The Orbital Observatory “Spektr-RG” (SRG) was launched to the halo orbit around the L2 point 1.5 million km away from the Earth with the PROTON launcher on July 13th, 2019. It scanned the whole sky twice already and created the map of the Universe and the “Milky Way” Galaxy in X-Rays. More than a million supermassive accreting black holes in quasars and Active Galactic Nuclei at cosmological distances up to z=6.2 are detected already. The observations of the clusters of galaxies (most massive gravitationally bound objects in the Universe) demonstrated that X-Ray sky surveys could still compete with the microwave SZ-effect sky surveys. We plan to use this giant amount of bright objects at high z to study the growth of the large scale structure of the Universe using Baryonic Acoustic Oscillations and other cosmological tests during and after reionization. I plan to mention the discovery of “eRosita Bubbles” above and below the plane of our Galaxy, detection of X-Ray emission from hundreds of stars with exoplanets, Tidal Disruption Events and very strong variability of the X-Ray sky on the half a year time scale. REGISTER FOR THE EVENT: Register in advance for this webinar: https://zoom.us/webinar/register/WN_mavq6fWGSlWo_ueIj-amsg After registering, you will receive a confirmation email containing information about joining the webinar. Should you not be able to join the Webinar, the Colloquium is also available in live streaming at: ictp.it/livestream. A detailed programme outline will be available shortly. About the ICTP Dirac Medal First awarded in 1985, ICTP's Dirac Medal is given in honor of P.A.M. Dirac, one of the greatest physicists of the 20th century and a staunch friend of the Centre. It is awarded every year on Dirac's birthday, 8 August, to scientists who have made significant contributions to theoretical physics. For more details about the prize and a list of past winners, see: https://www.ictp.it/about-ictp/prizes-awards/the-dirac-medal.aspx.