• TAPOMOY GUHA SARKAR

      Articles written in Journal of Astrophysics and Astronomy

    • Cosmology and Astrophysics using the Post-Reionization HI

      Tapomoy Guha Sarkar Anjan A. Sen

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      We discuss the prospects of using the redshifted 21-cm emission from neutral hydrogen in the post-reionization epoch to study our Universe. The main aim of the article is to highlight the efforts of Indian scientists in this area with the SKA in mind. It turns out that the intensity mapping surveys from SKA can be instrumental in obtaining tighter constraints on the dark energy models. Cross-correlation of the HI intensity maps with the Ly α forest data can also be useful in measuring the BAO scale.

    • Intensity mapping of post-reionization 21-cm signal and its cross-correlations as a probe of $f(R)$ gravity

      CHANDRACHUD B. V. DASH TAPOMOY GUHA SARKAR ANJAN KUMAR SARKAR

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      We propose the intensity mapping of the redshifted Hi 21-cm signal from the post-reionization epoch as a cosmological probe of $f(R)$ gravity. We consider the Hu–Sawicki family of $f(R)$ gravity models characterized by a single parameter $f_{,R0}$. The $f(R)$ modification to gravity affects the post-reionization 21-cm power spectrum through the change in the growth rate of density fluctuations. We find that a radio interferometric observation with a SKA1-mid-like radio telescope in both auto-correlation and cross-correlation with galaxy weak-lensing and Lyman-$\alpha$ forest may distinguish $f(R)$ models from $\Lambda$CDM cosmology at a precision, whichis competitive with other probes of $f(R)$ gravity.

  • Journal of Astrophysics and Astronomy | News

    • Continuous Article Publication

      Posted on January 27, 2016

      Since January 2016, the Journal of Astrophysics and Astronomy has moved to Continuous Article Publishing (CAP) mode. This means that each accepted article is being published immediately online with DOI and article citation ID with starting page number 1. Articles are also visible in Web of Science immediately. All these have helped shorten the publication time and have improved the visibility of the articles.

    • Editorial Note on Continuous Article Publication

      Posted on July 25, 2019

      Click here for Editorial Note on CAP Mode

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