December 05, 2025
(CET = Central European Time, IST = Indian Standard Time)
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13:30 - 14:15 CET / 18:00 - 18:45 IST
Speaker: Karčiauskas Mindaugas (Center for Physical Sciences and Technology (FTMC), Lithuania)
Title: Primordial Black Holes from Resonances in the Running-Mass-Inflation Model
Abstract: The Running-Mass-Inflation (RMI) model generates the primordial curvature perturbation spectrum that is consistent with observations at the pivot scale, but exhibits a very large running at smaller scales. This creates favourable conditions for the formation of Primordial Black Holes (PBHs). We propose a mechanism, based on the tachyonic trap scenario, that resonantly amplifies the curvature perturbation even further and provides the graceful exit for RMI. This makes it possible to compute the shape of the full perturbation spectrum as well as masses and abundances of PBHs. Such PBHs can explain Dark Matter. Moreover, the large curvature perturbation and PBH mergers generate gravitational waves that could be detected by space-based interferometers and resonant cavity experiments. The seminar will be based on our recent paper 2511.23182 [astro-ph.CO].
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12:45 - 13:30 CET / 17:15 - 18:00 IST
Speaker: Saurya Das (University of Lethbridge)
Title: A singularity free classical theory of gravity
Abstract: We present a classical theory of gravity, which is singularity free at short distances and reduces to General Relativity at large distances. We discuss its implications for quantum gravity and cosmology.
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