A5100339716- Galaxies: Formation, Evolution, Phenomena
- Cosmology and Gravitation Theories
- Black Holes and Theoretical Physics
- Gamma-ray bursts and supernovae
- Astrophysical Phenomena and Observations
- Astrophysics and Star Formation Studies
- Astronomy and Astrophysical Research
- Stellar, planetary, and galactic studies
- Noncommutative and Quantum Gravity Theories
- Astrophysics and Cosmic Phenomena
- Quantum Chromodynamics and Particle Interactions
- Geophysics and Gravity Measurements
- Pulsars and Gravitational Waves Research
- Superconducting and THz Device Technology
- Particle physics theoretical and experimental studies
- Radio Astronomy Observations and Technology
- Inflammatory Bowel Disease
- High-Energy Particle Collisions Research
- Nuclear physics research studies
- Solar and Space Plasma Dynamics
- Dark Matter and Cosmic Phenomena
- Adaptive optics and wavefront sensing
- Microwave Engineering and Waveguides
- Radio Frequency Integrated Circuit Design
- Geological and Geochemical Analysis
Sun Yat-sen University
2015-2025
Sixth Affiliated Hospital of Sun Yat-sen University
2023-2025
Capital University of Economics and Business
2024
Zhejiang University
2013-2024
Shandong University
2024
Flatiron Health (United States)
2018-2023
Flatiron Institute
2018-2023
Zhejiang Cancer Hospital
2023
Second Affiliated Hospital of Zhejiang University
2023
First Affiliated Hospital of Xi'an Jiaotong University
2022
A model for holographic dark energy is proposed, following the idea that short distance cut-off related to infrared cut-off. We assume relevant size of event horizon. With input $\Omega_\Lambda=0.73$, we predict equation state at present time be characterized by $w=-0.90$. The cosmic coincidence problem can resolved inflation in our scenario, provided minimal number e-folds.
We review the problem of dark energy, including a survey theoretical models and some aspects numerical studies.
We study the model for holographic dark energy in a spatially closed universe, generalizing proposal hep-th/0403127 flat universe. provide independent arguments choice of parameter c = 1 model. On one hand, cannot be less than 1, to avoid violating second law thermodynamics. other observation suggests very close 1; it is hard justify small deviation from if c>1.
The holographic principle of quantum gravity theory has been applied to the dark energy (DE) problem, and so far three DE models have proposed: original (HDE) model, agegraphic (ADE) Ricci (RDE) model. In this work, we perform best-fit analysis on these models, by using latest observational data including Union+CFA3 sample 397 Type Ia supernovae (SNIa), shift parameter cosmic microwave background (CMB) given five-year Wilkinson Microwave Anisotropy Probe (WMAP5) observations, baryon acoustic...
We perform a detailed investigation on the cosmological constraints holographic dark energy (HDE) model by using Plank data. find that HDE can provide good fit to high-ℓ (ℓ ≳ 40) temperature power spectrum, while discrepancy at ℓ ≃ 20-40 found in ΛCDM remains unsolved model. The data alone lead strong and reliable constraint parameter c. At 68% confidence level (CL), we obtain c = 0.508 ± 0.207 with Plank+WP+lensing, favoring present phantom behavior of more than 2σ CL. By combining Plank+WP...
Galactic outflows are ubiquitously observed in star-forming disk galaxies and critical for galaxy formation. Supernovae (SNe) play the key role driving outflows, but there is no consensus as to how much energy, mass metal they can launch out of disk. We perform 3D, high-resolution hydrodynamic simulations study SNe-driven from stratified media. Assuming SN rate scales with gas surface density $\Sigma_{\rm{gas}}$ Kennicutt-Schmidt (KS) relation, we find loading factor, $\eta_m$, defined...
We present the first results from an optical reverberation mapping campaign executed in 2014, targeting active galactic nuclei (AGN) MCG+08-11-011, NGC 2617, 4051, 3C 382, and Mrk 374. Our targets have diverse interesting observational properties, including a "changing look" AGN broad-line radio galaxy. Based on continuum-H$\beta$ lags, we measure black hole masses for all five targets. also obtain H$\gamma$ He{\sc ii}\,$\lambda 4686$ lags objects except 382. The indicate radial...
We discuss the anthropic principle when applied to holographic dark energy. find that if amplitude of density fluctuation is variable, energy fares better than cosmological constant. More generally, predictions agree with observation for wΛ = pΛ/ρΛ decreasing over time.
In this paper we place observational constraints on the interaction and spatial curvature in holographic dark energy model. We consider three kinds of phenomenological interactions between matter, i.e., term Q is proportional to densities (ρΛ), matter (ρm), plus (ρm+ρΛ). For probing model, use latest data including type Ia supernovae (SNIa) Constitution data, shift parameter cosmic microwave background (CMB) given by five-year Wilkinson Microwave Anisotropy Probe (WMAP5) observations, baryon...
We study the perturbation of holographic dark energy and find it to be stable. fate universe when interacting is present, discuss a simple phenomenological classification models. also cosmic coincidence problem in context energy. that cannot completely solved by adding an term. Inflation may provide better solution problem.
We prove that, in general, the first law of black hole thermodynamics, $\delta Q=T\delta S$, is violated $f(T)$ gravity. As a result, it possible that there exists entropy production, which implies thermodynamics can be non-equilibrium even static spacetime. This feature very different from $f(R)$ or other higher derivative gravity theories. find violation results lack local Lorentz invariance By investigating two examples, we note $f"(0)$ should negative order to avoid naked singularities...
The origins of the ~10^9 Msun quasar supermassive black holes (BHs) at redshifts z > 6 remain a theoretical puzzle. One possibility is that they grew from ~10^5 BHs formed in 'direct collapse' pristine, atomic-cooling (temperatures T ~ 8000 K; PAC) gas did not fragment to form ordinary stars due lack molecular hydrogen and metals. We propose baryonic streaming---the relic relative motion with respect dark matter cosmological recombination---provides natural mechanism for establishing...
We present the results of an optical spectroscopic monitoring program targeting NGC 5548 as part a larger multi-wavelength reverberation mapping campaign. The campaign spanned six months and achieved almost daily cadence with observations from five ground-based telescopes. H$\beta$ He II $\lambda$4686 broad emission-line light curves lag that 5100 $\AA$ continuum by $4.17^{+0.36}_{-0.36}$ days $0.79^{+0.35}_{-0.34}$ days, respectively. relative to 1158 ultraviolet curve measured Hubble Space...
Enzo (Enzo Developers, 2019a) is a block-structured adaptive mesh refinement code that widely used to simulate astrophysical fluid flows (primarily, but not exclusively, cosmological structure formation, star and turbulence).The community project with dozens of users, has contributed hundreds peer-reviewed publications in astrophysics, physics, computer science.The utilizes Cartesian can be run one, two, or
Abstract We present optical continuum lags for two Seyfert 1 galaxies, MCG+08-11-011 and NGC 2617, using monitoring data from a reverberation mapping campaign carried out in 2014. Our light curves span the ugriz filters over four months, with median cadences of 1.0 0.6 days respectively, combined roughly daily X-ray near-UV Swift 2617. find consistent geometrically thin accretion-disk models that predict lag-wavelength relation τ ∝ λ 4/3 . However, observed are larger than predictions based...
Stars form in galaxies, from gas that has been accreted the intergalactic medium. Simulations have shown recycling of gas-the reaccretion was previously ejected a galaxy-could sustain star formation early Universe. We observe surrounding massive galaxy at redshift 2.3 and detect emission lines neutral hydrogen, helium, ionized carbon extend 100 kiloparsecs galaxy. The kinematics this circumgalactic is consistent with an inspiraling stream. abundance indicates had already enriched elements...
Three ΔI=1 bands with the πg_{9/2}⊗νg_{9/2} configuration have been identified in _{35}^{74}Br_{39}. Angular distribution, linear polarization, and lifetime measurements were performed to determine multipolarity, type, mixing ratio, absolute transition probability of transitions. By comparing these experimental observations corresponding fingerprints quantum particle rotor model calculations, second third lowest are, respectively, suggested as chiral partner one-phonon wobbling excitation...
We argue that the space-time uncertainty relation of form $\ensuremath{\Delta}X\ensuremath{\Delta}T\ensuremath{\gtrsim}{\ensuremath{\alpha}}^{\ensuremath{'}}$ for observability distances with respect to time, $\ensuremath{\Delta}T$, and space, $\ensuremath{\Delta}X$, is universally valid in string theory including D-branes. This has been previously proposed by one (T. Y.) present authors as a simple qualitative representation perturbative short-distance structure fundamental theory. show...
Supernovae (SN), the most energetic stellar feedback mechanism, are crucial for regulating interstellar medium (ISM) and launching galactic winds. We explore how supernova remnants (SNRs) create a multiphase by performing 3D hydrodynamical simulations at various SN rates, $S$, ISM average densities, $\bar{n}$. The evolution of SNR in self-consistently generated three-phase is qualitatively different from that uniform or two-phase warm/cold medium. By travelling faster further low-density hot...
The presence of quasars at redshifts z > 6 indicates the existence supermassive black holes (SMBHs) as massive a few times 10^9 Msun, challenging models for SMBH formation. One pathway is through direct collapse gas in T_{vir} 10^4 K halos; however, this requires suppression H_2 cooling to prevent fragmentation. In paper, we examine proposed new mechanism which relies on cold-mode accretion flows leading shocks high densities (n cm^{-3}) and temperatures (T K). such gas, efficiently...