|Saturday 23 October 2021|
|Events for day: Wednesday 22 September 2021|
| 11:00 - 12:00 Wednesday Weekly Seminar - google meet|
Filtered asymmetric dark matter during the Peccei-Quinn phase transition
PARTICLES AND ACCELERATORS
Abstract: In this talk, I present a bubble filtering-out mechanism for an asymmetric dark matter scenario during the Peccei-Quinn (PQ) phase transition. Based on a QCD axion model, extended by extra chiral neutrinos, I show that the PQ phase transition can be first order in the parameter space of the model and regarding the PQ symmetry breaking scale, the mechanism can generate PeV-scale heavy neutrinos as a dark matter candidate. Considering a CP-violating source, during the phase transition, discriminating between the neutrino and antineutrino number density, the observed dark matter relic abundance is found. I then obtain effective couplin ...
13:30 - 15:00 Weekly Seminar (Online)
Gravity and cosmology beyond general relativity and gravitational waves
After motivating gravity and cosmology beyond general relativity, I will discuss some theories and their phenomenology, including gravitational waves ...
14:00 - 15:00 Weekly Seminar
Taming Active Matter: from ordered topological defects to autonomous shells
The spontaneous emergence of collective flows is a generic property of active fluids and often leads to chaotic flow patterns characterized by swirls, jets, and topological disclinations in their orientation field. I will first discuss two examples of these collective features helping us understand biological processes:
(i) to explain the tortoise & hare story in bacterial competition: how motility of Pseudomonas aeruginosa bacteria leads to a slower invasion of bacteria colonies, which are individually faster, and
(ii) how self-propelled defects lead to finding an unanticipated mechanism for cell death.
16:30 - 17:30 Fun with Curves
ISFAHAN BRANCH OF MATHEMATICS