535 citations · 1.3k across the 28 of their papers we have counts for
23 papers · 1 filter
Probing (sub-)solar-mass black holes and superspinars with current and next-generation gravitational-wave observatories
K. S. Sruthy, N. V. Krishnendu, Chandrachur Chakraborty +1
Gravitational-wave observations provide a powerful probe of compact objects and strong-field gravity. In this work, we investigate the detectability of binaries containing (sub-)so…
Implications of GW241011 for rotating exotic compact objects
N. V. Krishnendu, Tamara Evstafyeva, Aditya Vijaykumar +17
A number of theoretical proposals have been made for horizonless compact objects with masses and spins similar to those of black holes. While gravitational wave signatures from the…
Decadal upgrade strategy for KAGRA toward post-O5 gravitational-wave astronomy
KAGRA Collaboration, T. Akutsu, M. Ando +150
The KAGRA Collaboration has investigated a ten-year upgrade strategy for the KAGRA gravitational wave detector, considering a total of 14 upgrade options that vary in mirror mass,…
Identification of Noise-Associated Glitches in KAGRA O3GK with Hveto
T. Akutsu, M. Ando, M. Aoumi +148
Transient noise ("glitches") in gravitational wave detectors can mimic or obscure true signals, significantly reducing detection sensitivity. Identifying and excluding glitch-conta…
Searching for gravitational wave echoes from black hole binary events in the third observing run of LIGO, Virgo, and KAGRA collaborations
Nami Uchikata, Tatsuya Narikawa, Hiroyuki Nakano +3
Gravitational wave echo signals have been proposed as evidence for the modification of the spacetime structure near the classical event horizon. These signals are expected to occur…
Input optics systems of the KAGRA detector during O3GK
T. Akutsu, M. Ando, K. Arai +246
KAGRA, the underground and cryogenic gravitational-wave detector, was operated for its solo observation from February 25th to March 10th, 2020, and its first joint observation with…
Follow-up analyses of the binary-neutron-star signals GW170817 and GW190425 by using post-Newtonian waveform models
Tatsuya Narikawa, Nami Uchikata
We reanalyze the binary-neutron-star signals, GW170817 and GW190425, focusing on the inspiral regime to avoid uncertainties on waveform modeling in the postinspiral regime. We use…
Gravitational-wave constraints on the GWTC-2 events by measuring the tidal deformability and the spin-induced quadrupole moment
Tatsuya Narikawa, Nami Uchikata, Takahiro Tanaka
Gravitational waves from compact binary coalescences provide a unique laboratory to test properties of compact objects. As alternatives to the ordinary black holes in general relat…
Prospects for estimating parameters from gravitational waves of superspinar binaries
Nami Uchikata, Tatsuya Narikawa
To date, close to fifty presumed black hole binary mergers were observed by the LIGO and Virgo detectors. The analyses have been done with an assumption that these objects are blac…
Gravitational Wave Physics and Astronomy in the nascent era
Makoto Arimoto, Hideki Asada, Michael L. Cherry +50
The detections of gravitational waves (GW) by LIGO/Virgo collaborations provide various possibilities to physics and astronomy. We are quite sure that GW observations will develop…
Overview of KAGRA : KAGRA science
KAGRA Collaboration, T. Akutsu, M. Ando +240
KAGRA is a newly build gravitational-wave observatory, a laser interferometer with 3 km arm length, located in Kamioka, Gifu, Japan. In this paper in the series of KAGRA-featured a…
Black hole spectroscopy for KAGRA future prospect in O5
Nami Uchikata, Tatsuya Narikawa, Kazuki Sakai +2
Ringdown gravitational waves of compact binary mergers are an important target to test general relativity. The main components of the ringdown waveform after merger are black hole…
Reanalysis of the binary neutron star mergers GW170817 and GW190425 using numerical-relativity calibrated waveform models
Tatsuya Narikawa, Nami Uchikata, Kyohei Kawaguchi +4
We reanalyze gravitational waves from binary-neutron-star mergers GW170817 and GW190425 using a numerical-relativity (NR) calibrated waveform model, the TF2+_Kyoto model, which inc…
Searching for black hole echoes from the LIGO-Virgo Catalog GWTC-1
Nami Uchikata, Hiroyuki Nakano, Tatsuya Narikawa +3
We have examined gravitational wave echo signals for nine binary black hole merger events observed by Advanced LIGO and Virgo during the first and second observation runs. To const…
KAGRA: 2.5 Generation Interferometric Gravitational Wave Detector
T. Akutsu, M. Ando, K. Arai +188
The recent detections of gravitational waves (GWs) reported by LIGO/Virgo collaborations have made significant impact on physics and astronomy. A global network of GW detectors wil…
Comparison of various methods to extract ringdown frequency from gravitational wave data
Hiroyuki Nakano, Tatsuya Narikawa, Ken-ichi Oohara +7
The ringdown part of gravitational waves in the final stage of merger of compact objects tells us the nature of strong gravity which can be used for testing the theories of gravity…
Construction of KAGRA: an Underground Gravitational Wave Observatory
T. Akutsu, M. Ando, S. Araki +222
Major construction and initial-phase operation of a second-generation gravitational-wave detector KAGRA has been completed. The entire 3-km detector is installed underground in a m…
The status of KAGRA underground cryogenic gravitational wave telescope
KAGRA Collaboration, T. Akutsu, M. Ando +146
KAGRA is a 3-km interferometric gravitational wave telescope located in the Kamioka mine in Japan. It is the first km-class gravitational wave telescope constructed underground to…
Tidal deformability and I-Love-Q relations for gravastars with polytropic thin shells
Nami Uchikata, Shijun Yoshida, Paolo Pani
The moment of inertia, the spin-induced quadrupole moment, and the tidal Love number of neutron-star and quark-star models are related through some relations which depend only mild…
Slowly rotating thin shell gravastars
Nami Uchikata, Shijun Yoshida
We construct the solutions of slowly rotating gravastars with a thin shell. In the zero-rotation limit, we consider the gravastar composed of a de Sitter core, a thin shell, and Sc…
Slowly rotating regular black holes with a charged thin shell
Nami Uchikata, Shijun Yoshida
We obtain rotating solutions of regular black holes which are constructed of de Sitter spacetime with the axisymmetric stationary perturbation within the timelike charged thin shel…
New solutions of charged regular black holes and their stability
Nami Uchikata, Shijun Yoshida, Toshifumi Futamase
We construct new regular black hole solutions by matching the de Sitter solution and the Reissner-Nordstrom solution with a timelike thin shell. The thin shell is assumed to have m…
Quasinormal modes of a massless charged scalar field on a small Reissner-Nordström-anti-de Sitter black hole
Nami Uchikata, Shijun Yoshida
We investigate quasinormal modes of a massless charged scalar field on a small Reissner-Nordström-anti-de Sitter (RN-AdS) black hole both with analytical and numerical approaches.…