A5012911384- Pulsars and Gravitational Waves Research
- Gamma-ray bursts and supernovae
- Geophysics and Gravity Measurements
- Astrophysical Phenomena and Observations
- Cosmology and Gravitation Theories
- Radio Astronomy Observations and Technology
- Seismic Imaging and Inversion Techniques
- High-pressure geophysics and materials
- Astrophysics and Cosmic Phenomena
- Black Holes and Theoretical Physics
- Geophysics and Sensor Technology
- Numerical methods in engineering
- Computational Physics and Python Applications
- Dark Matter and Cosmic Phenomena
- Seismic Waves and Analysis
- Statistical and numerical algorithms
- Atomic and Subatomic Physics Research
- Magnetic confinement fusion research
- Electromagnetic Scattering and Analysis
- Adaptive optics and wavefront sensing
- Mechanical and Optical Resonators
- Electromagnetic Simulation and Numerical Methods
- Image and Object Detection Techniques
- Optical Systems and Laser Technology
- Experimental Learning in Engineering
Indian Institute of Technology Gandhinagar
2013-2025
University of California, Santa Cruz
2023
Goddard Space Flight Center
2014
California Institute of Technology
2010
Cardiff University
2006-2008
Inter-University Centre for Astronomy and Astrophysics
2002-2003
This paper presents the Summed Parallel Infinite Impulse Response (SPIIR) pipeline used for public alerts during third advanced LIGO and Virgo observation run (O3 run). The SPIIR uses infinite impulse response (IIR) filters to perform extremely low-latency matched filtering this process is further accelerated with graphics processing units (GPUs). It first online select candidates from multiple detectors using a coherent statistic based on maximum network likelihood ratio principle. Here we...
Several rapid parameter estimation methods have recently been advanced to deal with the computational challenges of problem Bayesian inference properties compact binary sources detected in upcoming science runs terrestrial network gravitational wave detectors. Some these are well-optimized reconstruct signals nearly real-time necessary for multimessenger astronomy. In this context, work presents a new, computationally efficient algorithm fast evaluation likelihood function using combination...
The number of gravitational wave signals from the merger compact binary systems detected in network advanced LIGO and Virgo detectors is expected to increase considerably upcoming science runs. Once a confident detection made, it crucial reconstruct source's properties rapidly, particularly sky position chirp mass, follow up on these transient sources with telescopes operating at different electromagnetic bands for multimessenger astronomy. In this context, we present rapid parameter...
Recent discoveries of gravitational wave (GW) signals from astrophysical compact binary systems neutron stars and black holes have firmly established them as prime sources for advanced GW detectors. Theoretical templates expected such been used to filter the detector data using matched filtering technique. An efficient grid over parameter space at a fixed minimal match has direct impact on improving computational efficiency these searches. We present construction three dimensional template...
We study the phenomenological consequences of amplitude-corrected post-Newtonian (PN) gravitational waveforms, as opposed to more commonly used restricted PN for quasi-circular, adiabatic inspiral compact binary objects. In case initial detectors it has been shown that use waveforms detection templates would lead significantly lower signal-to-noise ratios (SNRs) than those suggested by simulations based exclusively on waveforms. further elucidate origin effect an in-depth analytic treatment....
Astrophysical compact binary systems consisting of neutron stars and black holes are an important class gravitational wave (GW) sources for advanced LIGO detectors. Accurate theoretical waveform models from the inspiral, merger, ringdown phases such used to filter detector data under template-based matched-filtering paradigm. An efficient grid over parameter space at a fixed minimal match has direct impact on overall time taken by these searches. We present new hybrid geometric-random...
We study parameter estimation with post-Newtonian (PN) gravitational waveforms for the quasi-circular, adiabatic inspiral of spinning binary compact objects. In particular, performance amplitude-corrected is compared that more commonly used restricted waveforms, in Advanced LIGO and EGO. With properties source can only be extracted from phasing. case spectrum encodes a wealth additional information, which leads to dramatic improvements estimation. At distances ∼100 Mpc, full PN allow...
The higher multipoles of gravitational wave signals from coalescing compact binaries play a vital role in the accurate reconstruction source properties, bringing about deeper and nuanced understanding fundamental physics astrophysics. Their effect is most pronounced systems with asymmetric masses having an orbital geometry that not face-on. detection any single, isolated merger event challenging, as there much less power comparison to dominant quadrupole mode. In this paper, we present new...
LIGO-Aundha (A1), the Indian gravitational wave detector, is expected to join International Gravitational-Wave Observatory Network (IGWN) and begin operations in early 2030s. We study impact of this additional detector on accuracy determining direction incoming transient signals from coalescing binary neutron star (BNS) sources with moderately high signal-to-noise ratios. It conceivable that A1's sensitivity, effective bandwidth, duty cycle will improve incrementally through multiple...
Modeled searches of gravitational wave signals from compact binary mergers rely on template waveforms determined by the theory general relativity (GR). Once a signal is detected, one generally performs model agnostic test GR, either looking for consistency between GR waveform and data or introducing phenomenological deviations to detect departure GR. The nontrivial presence beyond-GR physics can alter could be missed template-based searches. A recent study [H. Narola et al., Beyond...
Accurate waveform models describing the complete evolution of compact binaries are crucial for maximum likelihood detection framework, testing predictions General Relativity (GR) and investigating possibility an alternative theory gravity. Deviations from GR could manifest in subtle variations numerical value GW signal's post-Newtonian (PN) phasing coefficients. Once search pipelines confirm unambiguous signal detection, deviations coefficients at various PN orders routinely measured...
The second postulate of special relativity states that the speed light in vacuum is independent emitter's motion. test this so far remains unexplored for gravitational radiation. We analyze data from LIGO-Virgo detectors to within ambit a model where emitted GWs (${c}^{\ensuremath{'}}$) binary depends on characteristic velocity $\stackrel{\texttildelow{}}{v}$ proportional reduced one-body system as ${c}^{\ensuremath{'}}=c+k\stackrel{\texttildelow{}}{v}$, $k$ constant. have estimated upper...
Coalescing compact binaries of neutron stars and/or black holes are considered as one the most promising sources for Earth based gravitational wave detectors. The LIGO-Virgo joint collaboration's Compact Binary Coalescence (CBC) group is searching waves emitted by these astrophysical systems matched filtering data against theoretically modeled template waveforms. A variety waveform families employed depending on mass range probed search and stage inspiral phase targeted: restricted...
Context. Adaptive optics (AO) is a technique for improving the resolution of ground-based telescopes by correcting optical aberrations due to atmospheric turbulence and telescope itself in real time. With rise giant segmented-mirror (GSMT), AO needed more than ever reach full potential these future observatories. One main performance drivers an system wavefront-sensing operation, consisting measuring shape described above. Aims. The nonmodulated pyramid wavefront sensor (nPWFS) with high...
This paper presents the SPIIR pipeline used for public alerts during third advanced LIGO and Virgo observation run (O3 run). The uses infinite impulse response (IIR) filters to perform extremely low-latency matched filtering this process is further accelerated with graphics processing units (GPUs). It first online select candidates from multiple detectors using a coherent statistic based on maximum network likelihood ratio principle. Here we simplify derivation of...
The first scientific runs of kilometer scale laser interferometric detectors like LIGO are underway. Data from these will be used to look for signatures gravitational waves (GW) astrophysical objects inspiraling neutron star/blackhole binaries using matched filtering. computational resources required online flat-search implementation the filtering large if searches carried out small total mass. In this paper we report an improved hierarchical search, wherein extend domain hierarchy extra...
Pattern matching techniques such as matched filtering will be used for online extraction of gravitational wave signals buried inside detector noise. This involves cross correlating the output with hundreds thousands templates spanning a multi-dimensional parameter space, which is very expensive computationally. A faster implementation algorithm was devised by Mohanty and Dhurandhar using hierarchy over mass parameters, speeded up procedure about 25–30 times. We show that further reduction in...
Random projection (RP) is a powerful dimension reduction technique widely used in the analysis of high dimensional data. We demonstrate how this can be to improve computational efficiency gravitational wave searches from compact binaries neutron stars or black holes. Improvements low-frequency response and bandwidth due detector hardware upgrades pose data challenge advanced LIGO era as they result increased redundancy template databases longer templates higher number signal cycles in-band....
Several theoretical waveform models have been developed over the years to capture gravitational wave emission from dynamical evolution of compact binary systems neutron stars and black holes. As ground-based detectors improve their sensitivity at low frequencies, real-time computation these waveforms can become computationally expensive, exacerbating steep cost rapidly reconstructing source parameters using Bayesian methods. This paper describes an efficient numerical algorithm for...
The Laser Interferometer Space Antenna (LISA) will be capable of detecting gravitational waves (GWs) in the milli-Hertz band. Among various sources, LISA detect coalescence supermassive black hole binaries (SMBHBs). Accurate and rapid inference parameters for such sources important potential electromagnetic follow-up efforts. Rapid Bayesian with includes additional complexities as compared to current generation terrestrial detectors terms time frequency dependent antenna response functions....
In this paper, we evaluate the potential of multiband gravitational wave observations to constrain properties static dark matter spikes around intermediate-mass ratio inspirals. The influence on orbital evolution compact binary is incorporated as a correction inspiral Newtonian waveform. We show that from proposed space-based detector GWSat, sensitive within deci-Hz frequency band, when combined with third-generation ground-based detectors like Einstein Telescope and Cosmic Explorer, will...
Low-latency gravitational wave search pipelines such as GstLAL take advantage of low-rank factorization the template matrix via singular value decomposition (SVD). With unprecedented improvements in detector bandwidth and sensitivity advanced-LIGO Virgo detectors, one expects several orders magnitude increase size banks. This poses a formidable computational challenge factorizing huge matrices. Previously, [in Kulkarni et al. [6]], we introduced idea random projection (RP)-based...