About me

Teaching

My research interests

My research is focused on investigating various primordial scenarios such as inflation, loop quantum cosmology and other bouncing scenarios. I am primarily interested in studying perturbations generated in these scenarios and investigating imprints of these perturbations in various observables. My Ph.D. thesis was titled "Computation and characteristics of inflationary three-point functions".

Topics of my interest include:

• Primordial non-Gaussianity

• Evolution of perturbations in an anisotropic background

• Features in primordial power spectrum

• Primordial black holes

• Relation between CMB anomalies and primordial physics

• Imprints of scale dependent primordial non-Gaussianity on CMB and LSS

• Model Comparison and constraining models using data

• Quantum to classical transition and measurement problem in Cosmology

I am also interested in various aspects of structure formation and the possibility of dark matter being a Bose-Einstein condensate.

Publications and pre-prints

My publications and preprints, in the reverse chronological order, is given below. They can also be found in arXiv, iNSPIRE and ORCiD.

1. Roshna K and V. Sreenath, Viability of loop quantum cosmology at the level of bispectrum, Submitted to the Proceedings of the Seventeenth Marcel Grossmann Meeting held at 'Gabriele d'Annunzio' University, Pescara, Italy from 7 - 12 July, 2024 [arXiv:2410.00614 [astro-ph.CO]].
2. Roshna K and V. Sreenath, Estimation of imprints of the bounce in loop quantum cosmology on the bispectra of cosmic microwave background, JCAP 08, 014 (2023) [arXiv:2301.05406 [astro-ph.CO]].
3. I. Agullo, D. Kranas and V. Sreenath, Anomalies in the Cosmic Microwave Background and their Non-Gaussian Origin in Loop Quantum Cosmology, Front. Astron. Space Sci. 8:703845 (2021) [arXiv:2105.12993 [gr-qc]].
4. A. Ashtekar, B. Gupt and V. Sreenath, Cosmic tango between the very small and the very large: Addressing CMB anomalies through Loop Quantum Cosmology, Front. Astron. Space Sci. 8:685288 (2021) [arXiv:2103.14568 [gr-qc]].
5. I. Agullo, D. Kranas and V. Sreenath, Large scale anomalies in the CMB and non-Gaussianity in bouncing cosmologies, Class. Quantum Grav. 38, 065010 (2021) [arXiv:2006.09605 [astro-ph.CO]].
6. I. Agullo, J. Olmedo and V. Sreenath, xAct Implementation of the Theory of Cosmological Perturbation in Bianchi I Spacetimes , Mathematics 2020, 8(2), 290 [arXiv:2006.03397 [gr-qc]].
7. I. Agullo, J. Olmedo and V. Sreenath, Observational consequences of Bianchi I spacetimes in loop quantum cosmology, Phys. Rev. D 102, 043523 (2020) [arXiv:2006.01883 [gr-qc]].
8. I. Agullo, D. Kranas and V. Sreenath, Anomalies in the CMB from a cosmic bounce, General Relativity and Gravitation 53, 17 (2021) [arXiv:2005.01796 [astro-ph.CO]].
9. I. Agullo, J. Olmedo and V. Sreenath, Hamiltonian theory of classical and quantum gauge invariant perturbations in Bianchi I spacetimes, Phys. Rev. D 101, 123531 (2020) [arXiv:2003.08428 [gr-qc]].
10. I. Agullo, J. Olmedo and V. Sreenath, Predictions for the CMB from an anisotropic quantum bounce, Phys. Rev. Lett. 124, 251301 (2020) [arXiv:2003.02304 [gr-qc]].
11. A. Ashtekar, B. Gupt, D. Jeong and V. Sreenath, Alleviating the tension in CMB using Planck-scale Physics, Phys. Rev. Lett. 125, 051302 (2020) [arXiv:2001.11689 [astro-ph.CO]].
12. V. Sreenath, I. Agullo and B. Bolliet, Computation of non-Gaussianity in loop quantum cosmology, [arXiv:1904.01075 [gr-qc]].
13. V. Sreenath, Spherical collapse of fuzzy dark matter, Phys. Rev. D 99, 043540 (2019) [arXiv:1808.08219 [astro-ph.CO]].
14. I. Agullo, B. Bolliet and V. Sreenath, Non-Gaussianity in Loop Quantum Cosmology, Phys. Rev. D 97, 066021 (2018) [arXiv:1712.08148 [gr-qc]].
15. D. Jaffino Stargen, V. Sreenath and L. Sriramkumar, Quantum-to-classical transition and imprints of continuous spontaneous localization in classical bouncing universes , IJMPD 30, 07, 2150049(2021) [arXiv:1605.07311 [gr-qc]].
16. D. Chowdhury, V. Sreenath and L. Sriramkumar, The scalar-scalar-tensor inflationary three-point function in the axion monodromy model, JCAP 1611, 041 (2016) [arXiv:1605.05292 [astro-ph.CO]].
17. D. Chowdhury, V. Sreenath and L. Sriramkumar, The tensor bi-spectrum in a matter bounce, JCAP 1511, 002 (2015) [arXiv:1506.06475 [astro-ph.CO]].
18. V. Sreenath, D. K. Hazra and L. Sriramkumar, On the scalar consistency relation away from slow roll, JCAP 1502, 029 (2015) [arXiv:1410.0252 [astro-ph.CO]].
19. V. Sreenath and L. Sriramkumar, Examining the consistency relations describing the three-point functions involving tensors, JCAP 1410, 021 (2014) [arXiv:1406.1609 [astro-ph.CO]].
20. V. Sreenath, R. Tibrewala and L. Sriramkumar, Numerical evaluation of the three-point scalar-tensor cross-correlations and the tensor bi-spectrum, JCAP 1312, 037 (2013) [arXiv:1309.7169 [astro-ph.CO]].
21. G. Santhosh, V. Sreenath, A. Lakshminarayan and R. Narayanan, Localized zero-energy modes in the Kitaev model with vacancy disorder, Phys. Rev. B 85, 054204 (2012) [arXiv:1106.2385 [cond-mat.str-el]].

Codes

As part of my research, I have contributed to the development of the following codes:

• A Mathematica code using the package xAct to compute second-order Hamiltonian of gauge invariant perturbations in Bianchi I spacetimes. The code is available at this URL.
• A C code based on the infrastructure provided by CLASS to calculate scalar non-Gaussianity generated in Loop Quantum Cosmology. The code is available at this URL.
• A Fortran code to evaluate inflationary three-point functions involving scalars and tensors for an arbitrary canonical single field inflationary model. The code is available at this URL.

Popular resources

Here, I provide links to some science resources that I find useful.

• IUCAA Scipop: A portal to IUCAA's outreach activites.
• Arvind Gupta Toys: Toys from trash and more.
• IAU resources: Astronomy resources from International Astronomical Union.
• ASTROEDU: Peer reviewed astronomy education activities.
• NASA: Educational resources.
• APOD: Astronomy picture of the day.
• NASA library: NASA image and video library.

Technical resources

Here, I provide links to some of the resources that I find useful.

Repositories:

• arXiv: A repository of e-prints.
• GitHub: Web based platform for version control based on Git.
• PLA: Planck legacy archive.
• PDG: Particle data group.

Cosmological Codes:

• CAMB: A boltzman solver in Fortran.
• COSMOMC: A Fortran code which performs cosmological montecarlo simulations and much more.
• CLASS: A boltzman solver in C.
• Monte Python: The Monte Carlo code for CLASS in Python.

Software tutorials:

• w3schools.com: A good tutorial for html and css.

Books

Here is a list of some books that I enjoyed reading:

• Apu trilogy: Pather Panjali, Aparajithan and Apuvinte lokam by Bibhutibhushan Bandopadhyay (Malayalam translation by M. K. N. Potty and Leela Sarkar)
• Aadujeevitham by Benyamin
• Ichamathi by Bibhutibhushan Bandopadhyay (Malayalam translation by Leela Sarkar)
• Of Human Bondage by W. Somerset Maugham
• Oru Sankeerthanam Pole by Perumbadavam Sreedharan
• Lust for Life by Irving Stone
• The Agony and the Ecstasy by Irving Stone
• Harry Potter series by J. K. Rowling
• 1Q84 by Haruki Murakami
• One Hundred Years of Solitude by Gabriel Garcia Marquez
• Quiet by Susan Cain
• Atlas Shrugged by Ayn Rand
• The Kite Runner by Khaled Hosseini
• A Thousand Splendid Suns by Khaled Hosseini
• Manjaveyil Maranangal by Benyamin
• The Razor's Edge by W. Somerset Maugham
• Iswaradarshanam by Swami Tapovanam (Malayalam translation by Swami Mridananda)
• Transition by Will Durant
• Gertrude by Hermann Hesse
• The Idiot by Fyodor Dostoevsky