Week 4 Activities at ICTS

Monday

10:30 to 12:00

Vaishak showed me what he does at ICTS and his area of research.

• Research regarding the gravitational waves emitted from binary black hole mergers.
• Runs numerical relativity code that analyses the data from LIGO to figure out the 15 parameters of black hole mergers:
  • Code from sxs and etk.
  • Also optimizes the numerical relativity code to work better on the supercomputers at ICTS.
• Visualization of these mergers using animations made using VisIT.
• Contributes to other git repositories such as nr catalog tools, which is a python package that provides a unified high-level interface to multiple catalogs of data products from Numerical Relativity simulations of compact-object binary mergers. It is a derivation of sxs collaboration.

Explained Newton-Raphson iterative procedure to find the root of a large equation, basically does this in 3D space and finds the...

3:30 to 4:30

Multi messenger cosmology with next-gen gravitational waves detectors and electromagnetic surveys by Sumit Kumar - Postdoc at Max Planck Institute for Gravitational Physics.

• Observational probes in cosmology:
  • CBR
  • SNLa light curves (supernovae)
  • Large scale structure of the universe is larger than 10 megaparsec
  • Baryon Acoustic Oscillation (part of the large scale structures)
• Current status of cosmology:
  • 69% dark energy
  • 26% dark matter
  • 5% Baryonic matter (includes protons, electrons, everything we know). Large part of the universe is dark energy and dark matter.
  • 4 evolutionary stages:
    • Early universe
    • Radiation dominated era
    • Matter dominated era
    • DE: Late time accelerated expansion
• Challenges:
  • Cosmological constant problem
  • Fine tuning problems
  • True nature of dark energy: e.g., cosmological constant or scalar field?
  • Nature of dark matter: Particle DM or modification of gravity
  • Hubble tension