1.1k citations · 2.7k across the 22 of their papers we have counts for
22 papers
KGCaRe: Explainable Complex Conditional Question Answering using Automatic Knowledge Graph Construction and Context Retrieval with LLMs
Ghanshyam Verma, Simanta Sarkar, Devishree Pillai +6
Answering complex conditional questions using Large Language Models (LLMs) and Retrieval-Augmented Generation (RAG) remains a challenge, particularly in domain-specific contexts wh…
Multi-output Headed Ensembles for Product Item Classification
Hotaka Shiokawa, Pradipto Das, Arthur Toth +1
In this paper, we revisit the problem of product item classification for large-scale e-commerce catalogs. The taxonomy of e-commerce catalogs consists of thousands of genres to whi…
Manipulating the nematic director by magnetic fields in the spin-triplet superconducting state of CuxBi2Se3
M. Yokoyama, H. Nishigaki, S. Ogawa +4
Electronic nematicity, a consequence of rotational symmetry breaking, is an emergent phenomenon in various new materials. In order to fully utilize the functions of these materials…
PATOKA: Simulating Electromagnetic Observables of Black Hole Accretion
George N. Wong, Ben S. Prather, Vedant Dhruv +11
The Event Horizon Telescope (EHT) has released analyses of reconstructed images of horizon-scale millimeter emission near the supermassive black hole at the center of the M87 galax…
PatchworkWave: A Multipatch Infrastructure for Multiphysics/Multiscale/Multiframe/Multimethod Simulations at Arbitrary Order
Dennis B. Bowen, Mark Avara, Vassilios Mewes +6
We present an extension of the PatchworkMHD code [1], itself an MHD-capable extension of the Patchwork code [2], for which several algorithms presented here were co-developed. Its…
First M87 Event Horizon Telescope Results. II. Array and Instrumentation
The Event Horizon Telescope Collaboration
The Event Horizon Telescope (EHT) is a very long baseline interferometry (VLBI) array that comprises millimeter- and submillimeter-wavelength telescopes separated by distances comp…
Dynamical Imaging with Interferometry
Michael D. Johnson, Katherine L. Bouman, Lindy Blackburn +7
By linking widely separated radio dishes, the technique of very long baseline interferometry (VLBI) can greatly enhance angular resolution in radio astronomy. However, at any given…
Time Domain Filtering of Resolved Images of Sgr A*
Hotaka Shiokawa, Charles F. Gammie, Sheperd S. Doeleman
The goal of the Event Horizon Telescope (EHT) is to provide spatially resolved images of Sgr A*, the source associated with the Galactic Center black hole. Because Sgr A* varies on…
Quantifying Intrinsic Variability of Sagittarius A* using Closure Phase Measurements of the Event Horizon Telescope
Freek Roelofs, Michael D. Johnson, Hotaka Shiokawa +2
General relativistic magnetohydrodynamic (GRMHD) simulations of accretion disks and jets associated with supermassive black holes show variability on a wide range of timescales. On…
PATCHWORK: A Multipatch Infrastructure for Multiphysics/Multiscale/Multiframe Fluid Simulations
Hotaka Shiokawa, Roseanne M. Cheng, Scott C. Noble +1
We present a "multipatch" infrastructure for numerical simulation of fluid problems in which sub-regions require different gridscales, different grid geometries, different physical…
The Intrinsic Shape of Sagittarius A* at 3.5-mm Wavelength
Gisela N. Ortiz-León, Michael D. Johnson, Sheperd S. Doeleman +19
The radio emission from Sgr A is thought to be powered by accretion onto a supermassive black hole of at the Galactic Center. At millimete…
Imaging an Event Horizon: Mitigation of Source Variability of Sagittarius A*
Ru-Sen Lu, Freek Roelofs, Vincent L. Fish +6
The black hole in the center of the Galaxy, associated with the compact source Sagittarius A* (Sgr A*), is predicted to cast a shadow upon the emission of the surrounding plasma fl…
General relativistic magnetohydrodynamical simulations of the jet in M87
Monika Moscibrodzka, Heino Falcke, Hotaka Shiokawa
(abridged) The connection between black hole, accretion disk, and radio jet can be best constrained by fitting models to observations of nearby low luminosity galactic nuclei, in p…
Measuring the Direction and Angular Velocity of a Black Hole Accretion Disk via Lagged Interferometric Covariance
Michael D. Johnson, Abraham Loeb, Hotaka Shiokawa +2
We show that interferometry can be applied to study irregular, rapidly rotating structures, as are expected in the turbulent accretion flow near a black hole. Specifically, we anal…
"Circularization" vs. Accretion -- What Powers Tidal Disruption Events?
Tsvi Piran, Gilad Svirski, Julian Krolik +2
A tidal disruption event (TDE) takes place when a star passes near enough to a massive black hole to be disrupted. About half the star's matter is given elliptical trajectories wit…
General Relativistic Hydrodynamic Simulation of Accretion Flow from a Stellar Tidal Disruption
Hotaka Shiokawa, Julian H. Krolik, Roseanne M. Cheng +2
We study how the matter dispersed when a supermassive black hole tidally disrupts a star joins an accretion flow. Combining a relativistic hydrodynamic simulation of the stellar di…
Observational appearance of inefficient accretion flows and jets in 3D GRMHD simulations: Application to Sgr~A*
Monika Moscibrodzka, Heino Falcke, Hotaka Shiokawa +1
Radiatively inefficient accretion flows (RIAFs) are believed to power supermassive black holes (SMBH) in the underluminous cores of galaxies. Such black holes are typically accompa…
The Galactic Center Weather Forecast
Monika Moscibrodzka, Hotaka Shiokawa, Charles F. Gammie +1
In accretion-based models for Sgr A* the X-ray, infrared, and millimeter emission arise in a hot, geometrically thick accretion flow close to the black hole. The spectrum and size…
Global GRMHD Simulations of Black Hole Accretion Flows: a Convergence Study
Hotaka Shiokawa, Joshua C. Dolence, Charles F. Gammie +1
Global, general relativistic magnetohydrodynamic (GRMHD) simulations of nonradiative, magnetized disks are widely used to model accreting black holes. We have performed a convergen…
Pair Production in Low Luminosity Galactic Nuclei
Monika Moscibrodzka, Charles F. Gammie, Joshua C. Dolence +1
Electron-positron pairs may be produced near accreting black holes by a variety of physical processes, and the resulting pair plasma may be accelerated and collimated into a relati…
Numerical Models of Sgr A*
M. Moscibrodzka, C. F. Gammie, J. Dolence +2
We review results from general relativistic axisymmetric magnetohydrodynamic simulations of accretion in Sgr A*. We use general relativistic radiative transfer methods and to produ…
Radiative Models of Sgr A* from GRMHD Simulations
Monika Moscibrodzka, Charles F. Gammie, Joshua C. Dolence +2
Using flow models based on axisymmetric general relativistic magnetohydrodynamics (GRMHD) simulations, we construct radiative models for sgr A*. Spectral energy distributions that…