Atrideb Chatterjee

Research Scholar
Email: atrideb [at]
Phone: +91 - 20 - 25719458
Extn: 9458
Office: F250
National Centre for Radio Astrophysics
Tata Institute of Fundamental Research
Savitribai Phule Pune University Campus,
Pune 411 007
Maharashtra, INDIA

Main Research Areas: Cosmology; Epoch of Reionization.

Supervisor: Tirthankar Roy Choudhury.


Atrideb obtained his B.Sc degree in Physics from Scottish Church College, University of Calcutta, in 2015. Following this, he joined NCRA-TIFR as an Integrated Ph.D. student. He completed the requirements of the NCRA-TIFR Graduate School in 2018, and is now working with Tirthankar Roy Choudhury for his doctoral research.

Research description:

The "cosmic dawn" refers to the epoch of formation of the first stars in the Universe. This is one of the most important phases in the study of cosmic galaxy and structure formation. According to the standard Big Bang model, the Universe was almost neutral around 400,000 years after the Big Bang. The subsequent physics of the Universe is straightforward and well-understood until the first stars start to form. It becomes largely uncertain once the first non-linear structures formed leading to cooling of gas and the formation of stars. One of the most important observational probes of the high redshift Universe is based on detecting the redshifted global 21~cm signal. This signal arises from the hyperfine splitting of the ground state of the hydrogen due to the magnetic moment interaction of the proton and electron. The strength of the signal depends on the difference between the hydrogen spin temperature and the background radiation temperature (i.e., that of the cosmic microwave background). The recent claim of the discovery of this signal from the cosmic dawn by the EDGES experiment has opened up a new window to investigate the physics of this epoch. More and more such studies are being planned, in order to detect and study this EoR signal. The main goal of my doctoral research would be to develop a detailed theoretical model of the cosmic dawn and couple with advanced statistical techniques to enable comparisons with available and upcoming data.

Selected publications:

1. "Ruling out 3 keV warm dark matter using 21-cm EDGES data",
 A. Chatterjee, P. Dayal, T. Roy Choudhury & A. Hutter, 2019, MNRAS, 487, 3560