148 citations
Counting papers with at most 25 authors, so collaboration author lists do not stand in for the people here.
- Seoul National UniversityKR34 papers
- Sungkyunkwan UniversityKR17 papers
- Yonsei UniversityKR16 papers
- Korea UniversityKR15 papers
- Korea Institute for Advanced StudyKR14 papers
- University of PittsburghUS14 papers
- High Energy Accelerator Research OrganizationJP11 papers
- Kyungpook National UniversityKR11 papers
- Institute for Basic ScienceKR10 papers
- New Generation University CollegeET10 papers
- Tohoku UniversityJP10 papers
- Chonnam National UniversityKR9 papers
17 papers · 1 filter
Perfect fluid with shear viscosity and spacetime evolution
Inyong Cho, Rajibul Shaikh
We investigate the anisotropic evolution of spacetime driven by perfect fluid with off-diagonal shear-viscosity components. We consider the simplest form of the equation of state f…
Testing black hole mimickers with the Event Horizon Telescope image of Sagittarius A
Rajibul Shaikh
The Event Horizon Telescope (EHT) has recently observed the image and shadow of the supermassive compact object Sagittarius A (Sgr A). According to the EHT collaboration, t…
Shadows in conformally related gravity theories
Kunal Pal, Kuntal Pal, Rajibul Shaikh +1
Null geodesics are invariant under a conformal transformation, and thus it might seem natural to assume that the observables corresponding to the shadow of a space-time are also co…
Numerical Study of Instability of Fluid Black Holes
Inyong Cho, Dong-Ho Park
Recently neutral and charged black-hole solutions were found for static perfect fluid with the equation of state , for fluid only as well as for fluid in the presence…
Second-order effective energy-momentum tensor of gravitational scalar perturbations with perfect fluid
Inyong Cho, Jinn-Ouk Gong, Seung Hun Oh
We investigate the second-order gravitational scalar perturbations for a barotropic fluid. We derive the effective energy-momentum tensor described by the quadratic terms of the gr…
Fluid Black Holes with Electric Field
Inyong Cho
We investigate the gravitational field of static perfect-fluid in the presence of electric field. We adopt the equation of state for the fluid in order to consider t…
Simple Black Holes with Anisotropic Fluid
Inyong Cho, Hyeong-Chan Kim
We study a spherically symmetric spacetime made of anisotropic fluid of which radial equation of state is given by . This provides analytic solutions and a good opportuni…
Static-Fluid Black Holes
Inyong Cho, Hyeong-Chan Kim
We investigate black holes formed by static perfect fluid with . These represent the black holes in and spatial geometries. There are three classes of black-hol…
Primordial Power Spectra of EiBI Inflation in Strong Gravity Limit
Inyong Cho, Naveen K. Singh
We investigate the scalar and the tensor perturbations of the inflation model in the strong-gravity limit of Eddington-inspired Born-Infeld (EiBI) theory. In order to conside…
Spectral indices in Eddington-inspired Born-Infeld inflation
Inyong Cho, Jinn-Ouk Gong
We investigate the scalar and tensor spectral indices of the quadratic inflation model in Eddington-inspired Born-Infeld (EiBI) gravity. We find that the EiBI corrections to the sp…
Tensor-to-Scalar Ratio in Eddington-inspired Born-Infeld Inflation
Inyong Cho, Naveen K. Singh
We investigate the scalar perturbation of the inflation model driven by a massive-scalar field in Eddington-inspired Born-Infeld gravity. We focus on the perturbation at the attrac…
Inflationary Tensor Perturbation in Eddington-inspired Born-Infeld gravity
Inyong Cho, Hyeong-Chan Kim
We investigate the tensor perturbation in the inflation model driven by a massive-scalar field in Eddington-inspired Born-Infeld gravity. For short wave-length modes, the perturbat…
Precursor of Inflation
Inyong Cho, Hyeong-Chan Kim, Taeyoon Moon
We investigate a nonsingular initial state of the Universe which leads to inflation naturally. The model is described by a scalar field with a quadratic potential in Eddington-insp…
A new synthesis of matter and gravity: A nongravitating scalar field
Inyong Cho, Hyeong-Chan Kim
We present a new manifestation of the nonlinearity of the gravity-matter interactions. We show explicitly that there exists a nongravitating dynamical scalar-field solution in Eddi…
Perturbations in Symmetric Lee-Wick Bouncing Universe
Inyong Cho, O-Kab Kwon
We investigate the tensor and the scalar perturbations in the symmetric bouncing universe driven by one ordinary field and its Lee-Wick partner field which is a ghost. We obtain th…
Universe Driven by Perfect Fluid in Eddington-inspired Born-Infeld Gravity
Inyong Cho, Hyeong-Chan Kim, Taeyoon Moon
We investigate the evolution of the Universe filled with barotropic perfect fluid in Eddington-inspired Born-Infeld gravity. We consider both the isotropic and the anisotropic univ…
Scalar Perturbation in Symmetric Lee-Wick Bouncing Universe
Inyong Cho, O-Kab Kwon
We investigate the scalar perturbation in the Lee-Wick bouncing universe driven by an ordinary scalar field plus a ghost field. We consider only a symmetric evolution of the univer…