| Saturday 19 April 2025 | |
| Events for day: Tuesday 13 August 2024 |
| 13:30 - 15:00 Special Seminar (online): Impact of AGN feedback on the dynamics of gas; A Review Across Diverse Environments School ASTRONOMY Massive stars (those ?8 solar masses at formation) have radiative envelopes that cannot sustain a dynamo, the mechanism that produces magnetic fields in lower-mass stars. Despite this, approximately 7% of massive stars have observed magnetic fields, the origin of which is debated. We used multi- epoch interferometric and spectroscopic observations to characterize HD 148937, a binary system of two massive stars. We found that only one star is magnetic and that it appears younger than its companion. The system properties and a surrounding bipolar nebula can be reproduced with a model in which two stars merged (in a previous triple system) to pr ... 14:00 - 15:00 Weekly Seminar HEPCo Group 2D Bi-Scalar Gravity from 4D Horndeski Theory School PHYSICS Date and time Tuesday, August 13th, 2024 (Mordad 23rd, 1403), 2:00 pm (Tehran zone) Link https://www.skyroom.online/ch/schoolofphysics/highenergyseminar Abstract In this talk, I will present aspects of 2D scalar-tensor theories. First, I will construct a 2D bi-scalar gravity from a 4D Horndeski theory using a Kaluza-Klein (KK) dimensional reduction on a 2-sphere. I will then provide some identities to write the action in a more compact form and use these to develop a more generalized 2D bi-scalar theory. Following this, I will u ... |