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I was a VESF fellow at LAL Orsay, and IAP Paris
and a postdoctoral research associate at the Washington University in St Louis.
I was a Ph.D. student of
Bala R Iyer at the Raman Research Institute. Email: kgarun at cmi dot ac point in |
Research Interests: Gravitational Wave Astronomy, General relativistic modelling of compact binaries, Tests of General Relativity using Gravitational Waves, Short Gamma Ray Bursts, High Energy Astophysics, Cosmology
List of my publications and their citations: Google Scholar Record, inspire, arXiv link
A quick summary of my research:
- General Relativistic modelling of compact binaries: I was involved in the computation of gravitational waveforms from compact binaries moving in circular orbits which are among the most promising sources for ground-based detectors such as LIGO and Virgo. For example, the 2.5 post-Newtonian (2.5PN) polarizations of compact binaries in circular orbits I computed with my collaborators in gr-qc/0404085 and the spin contribution to the gravitational wave polarizations computed in arXiv:0810.5336 are widely used in various parameter estimation studies and included in the GW data analysis pipelines.
- Gravitational Wave Data Analysis: I was involved in the analysis of the seventh commissioning run data (C7) of the Virgo interferometer in search of GW bursts reported here. Currently with a student of mine, Chinmay Kalaghatgi, and P Ajith, I am involved in the study of template placement of Inspiral-Merger-Ringdown waveforms in the searches for binary black hole signals.
- Tests of General Relativity and Alternative Theories of gravity using GWs observations: I studied the possibilities of testing General Relativity and other theories of gravity using GW observations. We put forward a parametrized phasing formula to capture generic deviations from GR and investigated the capabilities of various GW detectors to bound these parameters. A short review of the field can be found in my article with Archana Pai
- Association of Short Gamma Ray Bursts and Gravitational Waves: This is one of my recent interests. Compact binary mergers are not only the most promising sources of GWs, but also believed to be the progenitors of Short Gamma Ray Bursts (SGRBs). If this is the case, it is likely that some of the first GW events from NS-NS or NS-BH binaries may have an electromagnetic counterpart in the form of SGRBs and their afterglows. Such joint observations can be very useful in understanding the phenomenon better. We investigated the implications of such joint observations if the SGRBs are observed off-axis (jet axis of the SGRB not coinciding with observer's line of sight) and argued how such joint observations can help us probe (i) the SGRB jet structure, (ii) proposed fundamental correlation between energies associated with the GRB (Amati and Ghirlanda type relations) and (iii) searches for orphan afterglows. Our recent article can be found here . We are currently looking at various aspects related to the modelling of SGRB afterglow in the GW-SGRB era.
A pedagogical article on Gravitational Wave Astronomy that I wrote with P Ajith for Resonance magazine can be found here
Recent Papers:
- ``Gravitational Waves and Gamma-rays from a Binary Neutron Star Merger: GW170817 and GRB 170817A", Apj. Lett. 848, L13 (2017), arXiv
- ``GW170817: Observation of Gravitational Waves from a Binary Neutron Star Inspiral", Phys. Rev. Lett. 119, 161101 (2017), arXiv
- ``Implications of binary black hole detections on the merger rates of double neutron stars and neutron star-black holes", A. Gupta, K. G. Arun, B. S. Sathyaprakash, Apj. Letters 849, L14 (2017), arXiv.
- ``Testing the binary black hole nature of a compact binary coalescence", N. V. Krishnendu, K. G. Arun, C. K. Mishra, Phys. Rev. Lett. 119, 091101 (2017), arXiv.
- "GW170104: Observation of a 50-Solar-Mass Binary Black Hole Coalescence at Redshift 0.2", LSC and Virgo Collaboration, arXiv, Phys. Rev. Lett. 118, 221101 (2017)
- "Explosive and radio-selected Transients: Transient Astronomy with SKA and its Precursors", P. Chandra, G. C. Anupama, K. G. Arun et al arXiv, J Astrophys Astron (2016) 37: 30
- "Tests of general relativity with GW150914", LSC and Virgo Collaboration, arXiv, Phys. Rev. Lett. 116, 221101 (2016)
- "Observation of Gravitational Waves from a Binary Black Hole Merger", LSC and Virgo Collaboration, arXiv, Phys. Rev. Lett. 116, 061102 (2016)
- "Gravitational-wave phasing for low-eccentricity inspiralling compact binaries to 3PN order", arXiv (To appear in Phys. Rev. D.).
- "Ready-to-use post-Newtonian gravitational waveforms for binary black holes with non-precessing spins: An update ", arXiv, Phys. Rev. D 93, 084054 (2016)
Other Selected publications:
- "Synergy of short gamma ray burst and gravitational wave observations: Constraining the inclination angle of the binary and possible implications for off-axis GRBs"(2014): arXiv , Phys. Rev. D.
- "Third post-Newtonian angular momentum flux and the secular evolution of orbital elements for inspiralling compact binaries in quasi-elliptical orbits " (2009) arXiv Physical Review D
- "Parametrized tests of post-Newtonian theory using Advanced LIGO and Einstein Telescope" (2010) arXiv Physical Review D
- "Higher-order spin effects in the amplitude and phase of gravitational waveforms emitted by inspiraling compact binaries: Ready-to-use gravitational waveforms" (2009) arXiv Physical Review D
- "Higher signal harmonics, LISA's angular resolution, and dark energy" (2007) arXiv Physical Review D
- "Probing the non-linear structure of general relativity with black hole binaries" (2006) arXiv Physical Review D
- "Parameter estimation of inspiralling compact binaries using 3.5 post-Newtonian gravitational wave phasing: The non-spinning case"(2005) arXiv Physical Review D
- "The 2.5PN gravitational wave polarisations from inspiralling compact binaries in circular orbits"(2004) arXiv Classical and Quantum Gravity