Hyung Won Lee
A5100645253- Cosmology and Gravitation Theories
- Black Holes and Theoretical Physics
- Pulsars and Gravitational Waves Research
- Astrophysical Phenomena and Observations
- Galaxies: Formation, Evolution, Phenomena
- Gamma-ray bursts and supernovae
- Geophysics and Sensor Technology
- Noncommutative and Quantum Gravity Theories
- Advanced Differential Geometry Research
- Dark Matter and Cosmic Phenomena
- High-pressure geophysics and materials
- Seismic Waves and Analysis
- Geophysics and Gravity Measurements
- Quantum Electrodynamics and Casimir Effect
- Digital Radiography and Breast Imaging
- Advanced Semiconductor Detectors and Materials
- Pharmacogenetics and Drug Metabolism
- Particle physics theoretical and experimental studies
- Radiation Detection and Scintillator Technologies
- Medical Imaging Techniques and Applications
- Quantum Chromodynamics and Particle Interactions
- Magnetic confinement fusion research
- Astrophysics and Cosmic Phenomena
- Advanced X-ray and CT Imaging
- Ion Transport and Channel Regulation
Inje University
2012-2024
National Tsing Hua University
2023
Montclair State University
2022
Université Paris Cité
2021
The University of Tokyo
2020
Seoul National University Hospital
2017
International Center for Relativistic Astrophysics
2017
Korea Advanced Institute of Science and Technology
2005
National University of Singapore
2004
Peking University
2004
Abstract KAGRA is a newly built gravitational-wave telescope, laser interferometer comprising arms with length of 3 km, located in Kamioka, Gifu, Japan. was constructed under the ground and it operated using cryogenic mirrors that help reducing seismic thermal noise. Both technologies are expected to provide directions for future telescopes. In 2019, finished all installations designed configuration, which we call baseline KAGRA. For this occasion, present an overview from various viewpoints...
We investigate a model of the interacting holographic dark energy with cold matter (CDM). If density decays into CDM, we find two types effective equation state. In this case have to use equations state ($\omega^{\rm eff}_{\rm \Lambda}$) instead ($\omega_{\rm \Lambda})$. For fixed ratio densities, their are given by same negative constant. Actually, cosmic anti-friction arisen from vacuum decay process may induce acceleration $\omega^{\rm \Lambda}<-1/3$. variable ratio, slightly different,...
We investigate the agegraphic dark energy models which were recently proposed to explain energy-dominated universe. For this purpose, we calculate their equation of states and squared speeds sound. find that speed for is always negative. This means perfect fluid classically unstable. Furthermore, it shown new model could describe matter (radiation)-dominated universe in far past only when parameter $n$ chosen be $n>n_c$, where critical values are determined $n_c=2.6878(2.5137752)$...
KAGRA is a newly built gravitational wave observatory, laser interferometer with 3 km arm length, located in Kamioka, Gifu, Japan. In this series of articles, we present an overview the baseline KAGRA, for which finished installing designed configuration 2019. This article describes method calibration (CAL) used reconstructing signals from detector outputs, as well characterization (DET). We also review physical environmental monitors (PEM) system and geophysics (GIF). Both are...
The detection of ~50 coalescing compact binaries with the Advanced LIGO and Virgo detectors has allowed us to test general relativity, constrain merger rates, look for evidence tidal effects, object spins, higher waveform modes, black hole ringdowns. An effect that not yet been confidently detected is binary eccentricity, which might be present in a small fraction formed dynamically. Here we discuss limits on eccentricity can, in-principle, placed all types by detector operating at design...
Background Commonly occurring genetic variants in CYP2C9 are known to reduce catalytic activity and associated with enhanced patient sensitivity warfarin. Interethnic differences warfarin dose requirement have been described the Asian population, we postulate that this could be related of unique ethnic groups. Methods We prospectively genotyped 125 patients who were receiving a stable daily maintain international normalized ratio values between 2 3 through comprehensive sequencing promoter...
Major construction and initial-phase operation of a second-generation gravitational-wave detector KAGRA has been completed. The entire 3-km is installed underground in mine order to be isolated from background seismic vibrations on the surface. This allows us achieve good sensitivity at low frequencies high stability detector. Bare-bones equipment for interferometer first test run was accomplished March April 2016 with rather simple configuration. initial configuration named {\it iKAGRA}. In...
KAGRA is a second-generation interferometric gravitational-wave detector with 3-km arms constructed at Kamioka, Gifu in Japan. It now its final installation phase, which we call bKAGRA (baseline KAGRA), scientific observations expected to begin late 2019. One of the advantages underground location least 200 m below ground surface, brings small seismic motion low frequencies and high stability detector. Another advantage that it cools down sapphire test mass mirrors cryogenic temperatures...
We investigate the new agegraphic dark energy models with generalized uncertainty principle (GUP). It turns out that although GUP affects early universe, it does not change current and future energy-dominated universe significantly. Furthermore, this model could describe matter-dominated in past only when parameter n is chosen to be > c , where critical value determined = 2.799531478.
One of the major problems in Cosmology is fact that there no good candidate dark matter Standard Model Particle Physics or any experimentally supported modifications it. At same time, one General Relativity it cannot be unified with Quantum Theory. Here, we present a program to see if not common source both problems. The idea an interaction term between fields and gravitational field total Lagrangian, analogous for Electromagnetism, could possibly provide dynamical effect which postulated,...
We calculate the spectral index and tensor-to-scalar ratio for patch inflation arisen from Gauss-Bonnet braneworld scenario. The cosmological models consist of (GB), Randall-Sundrum (RS), 4D general relativistic (GR) cases. In order to compare with observation data, we perform leading-order calculations all by choosing large-field, small-field, hybrid potentials. show that large-field potentials are sensitive a given model, while small-field insensitive model. It is easier discriminates...
We investigate how the uncertainty of noncommutative spacetime affects on inflation. For this purpose, parameter $\mu_0$ is taken to be a zeroth order slow-roll parameter. calculate power spectrum up second using expansion. find corrections arisen from change pivot scale and presence variable parameter, when comparing with commutative spectrum. The power-law inflation chosen obtain explicit forms for spectrum, spectral index, running index. In cases effect higher-order compensates loss in...
We investigate a model of brane cosmology to find unified description the radiation-matter-dark energy universe. It is interacting holographic dark with bulk-holographic matter $χ$. This five-dimensional cold matter, which plays role radiation on brane. Using effective equations state $ω^{\rm eff}_{\rm Λ}$ instead native $ω_{\rm Λ}$, we show that this cannot accommodate any transition from Λ}\ge-1$ phantom regime Λ}
We study the entropy bound for local quantum field theory (LQFT) with generalized uncertainty principle. The principle provides naturally a UV cutoff to LQFT as gravity effects. Imposing non-gravitational collapse condition UV–IR relation, we find that maximal of bosonic is limited by A3/4 rather than A boundary area.
Modern ground-based gravitational wave (GW) detectors require a complex interferometer configuration with multiple coupled optical cavities.Since achieving the resonances of arm cavities is most challenging among lock acquisition processes, scheme called length stabilization (ALS) had been employed for cavities.We designed new type ALS, which compatible interferometers having long arms like next generation GW detectors.The features ALS are that control simpler than those previous ones and it...
We study the 5D black holes in type IIB superstring theory compactified on $S^1 \times T^4$. Far from horizon, we have flat space-time. Near $AdS_3(BTZ hole) S^3 calculate greybody factor of a minimally coupled scalar by replacing original geometry($M_5 S^1 T^4$) $AdS_3 In low-energy scattering, it turns out that result agrees with hole (or D1 + D5 branes)in dilute gas approximation. This confirms $AdS$-theory($AdS_3 contains essential information about bulk holes.
A vibration isolation system called the Type-Bp used for power recycling mirrors has been developed KAGRA, interferometric gravitational-wave observatory in Japan. suspension of passively isolates an optic from seismic using three main pendulum stages equipped with two vertical systems. compact reaction mass around each allows achieving sufficient damping performance a simple feedback as well ratio. Three systems were installed and proved to satisfy requirements on performance, also...