Seminar 1: Frequency Shift in Binary Lensing System

Samaneh Sarbaz

Department of Physics, Sharif University of Technology

Seminar 2: About Primordial Black Holes: From Inflation to Formation

Mohammad Amin Hejazi

Department of Physics, Sharif University of Technology

Abstract 1: Gravitational microlensing with binary lenses is one of the channels for the detection of exoplanets. Due to the degenerated nature of the solutions for the binary microlensing, additional features such as parallax and finite-size effects need to break the degeneracy between the lens parameters. Here in this work, we introduce the application of the frequency shift effect in the binary microlensing observations where the single lens has been studied in \cite{Rahvar_2020}. The frequency shift is the relativistic analogy of the gravity assist for the photons. We derive the frequency shift in the binary lenses and the relative frequency shift during the caustic crossing. We also investigate the practical feasibility of the detection of this effect by high-resolution spectrographs such as ESPRESSO in VLT telescope.

 

 

Abstract 2: Primordial black holes (PBHs) are a theoretical prediction from the early universe. They are believed to form when fluctuations with sufficient amplitude collapse after re-entering the Hubble horizon. Some observational evidence, such as heavy black hole mergers and the nature of dark matter, has sparked interest in PBH physics.

In this talk, I will provide an overview of PBHs, starting with their historical background and then discussing the formation process and the role of inflation. Finally, I will delve into PBH statistics and their constraints.

یکشنبه 18 تیر 1402، ساعت 10:00

Sunday 9 July 2023 – 10:00 Tehran Time

Hybrid Seminar

دانشکده فیزیک – طبقه 5 – اتاق 512Physics Department – fifth floor – Room 512/

https://vc.sharif.edu/ch/cosmology

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