Inflation on a Pair of D3-brane and D3bar-brane in Klebanov-Strassler Background (2009)
Kim, Yoonbai, Nakajima, Hiroaki, Ryu, Kyungha, Kim, Hang Bae
We explain how to obtain Klabanov-Strassler solution in the low-energy limit of type IIB superstring theory and describe slow-roll inflation on the system of parallely-separated D3-brane and...
INSTRUMENTATION AND CONTROL IN THE REPUBLIC OF KOREA (2008)
Nuclear Power Plant, Hang Bae Kim
In Korea, 20 units of Nuclear Power Plant (NPP) are in operation. As of 2006, the NPPs provide approximately 39 % of total electricity generation and cover 27 % of total generating capacity which is...
Flaxino dark matter and stau decay (2008)
Chun, Eung Jin, Kim, Hang Bae, Kohri, Kazunori, Lyth, David H.
If the spontaneous breaking of Peccei-Quinn symmetry comes from soft supersymmetry breaking, the fermionic partners of the symmetry-breaking fields have mass of order the gravitino mass, and are...
Axino Light Dark Matter and Neutrino Masses with R-parity Violation (2006)
Motivated by the recent observation of the 511 keV $\gamma$-ray line emissions from the galactic bulge and an explanation for it by the decays of light dark matter particles, we consider the light...
Cosmological Aspects of the D-brane World (2006)
Cho, Inyong, Chun, Eung Jin, Kim, Hang Bae, Kim, Yoonbai
The D-brane world is an idea that we are living on the D-brane imbedded in a 10- or 11-dimensional spacetime of string theories, aiming at the construction of realistic models from string theories....
String Cosmology of the D-brane Universe (2006)
Cho, Inyong, Chun, Eung Jin, Kim, Hang Bae, Kim, Yoonbai
We analyze homogeneous anisotropic cosmology driven by the dilaton and the self-interacting ``massive'' antisymmetric tensor field which are indispensable bosonic degrees with the graviton in the...
Cosmological implication of antisymmetric tensor field on D-brane (2006)
Cho, Inyong, Chun, Eung Jin, Kim, Hang Bae, Kim, Yoonbai
We discuss the cosmological implications of an antisymmetric tensor field when it experiences a kind of ``Higgs mechanism,'' including nonlocal interaction terms, on D-branes. Even when a huge...
Dilaton Stabilization and Inflation in the D-brane World (2005)
We study the dilaton stabilization in the D-brane world in which a D-brane constitutes our universe. The dilaton can be stabilized due to the interplay between the D-brane tension and the negative...
Cosmology of Antisymmetric Tensor Field in D-brane Universe (2005)
Chun, Eung Jin, Kim, Hang Bae, Kim, Yoonbai
We analyze homogeneous, anisotropic cosmology driven by a self-interacting ``massive'' antisymmetric tensor field $B_{\mu\nu}$ which is present in string theories with D-branes. Time-dependent...
Unstable D-branes and String Cosmology (2004)
Kim, Chanju, Kim, Hang Bae, Kim, Yoonbai, Kwon, O-Kab, Lee, Chong Oh
Cosmological implication of rolling tachyons is reported in the context of effective field theory. With a brief review of rolling tachyons in both flat and curved spacetimes, we study the string...
Constraining superheavy dark matter model of UHECR with SUGAR data (2003)
Kim, Hang Bae, Tinyakov, Peter
Models which associate the origin of the ultra-high energy cosmic rays (UHECR) with decays of relic superheavy particles predict the anisotropy of UHECR flux toward the Galactic center. We use the...
Cosmology of Rolling Tachyon (2003)
Kim, Chanju, Kim, Hang Bae, Kim, Yoonbai, Kwon, O-Kab
We study dynamics of rolling tachyon and Abelian gauge field on unstable D-branes, of which effective action is given by Born-Infeld type nonlocal action. Possible cosmological evolutions are also...
Electromagnetic String Fluid in Rolling Tachyon (2003)
Kim, Chanju, Kim, Hang Bae, Kim, Yoonbai, Kwon, O-Kab
We study Born-Infeld type effective action for unstable D3-brane system including a tachyon and an Abelian gauge field, and find the rolling tachyon with constant electric and magnetic fields as the...
Rolling Tachyons in String Cosmology (2002)
Kim, Chanju, Kim, Hang Bae, Kim, Yoonbai
We study the role of rolling tachyons in the cosmological model with dilatonic gravity. In the string frame, flat space solutions of both initial-stage and late-time are obtained in closed form. In...
Cosmology of Randall-Sundrum models (2001)
There are many interesting issues in the brane world with a large/warped extra dimension. We focus on the cosmological aspects. We review the cosmological solutions of the brane world and how the...
Covi, Laura, Kim, Hang Bae, Kim, Jihn E., Roszkowski, Leszek
Supersymmetric extensions of the Standard Model that incorporate the axion solution to the strong CP problem necessarily contain also the axino, the fermionic partner of the axion. In contrast to the...
Gravitino creation by an oscillating scalar field (2000)
This paper has been withdrawn because the analytic estimates are not confirmed by the numerical calculation of Nilles, Peloso and Sorbo (hep-ph/0102264 and hep-th/0103202).
Cosmological constraints on a Peccei-Quinn flatino as the lightest supersymmetric particle (2000)
Chun, Eung Jin, Kim, Hang Bae, Lyth, David H.
In an interesting class of models, non-renormalizable terms of the superpotential are responsible for the spontanteous breaking of Peccei-Quinn (PQ) symmetry as well as the generation of the $\mu$...
We provide the cosmological solutions for Randall-Sundrum models with the bulk energy-momentum $\hat T^5_5$ incorporated. It alters the Friedmann equation for the brane scale factor. We make a...
Inflation and Gauge Hierarchy in Randall-Sundrum Compactification (1999)
We obtain the general inflationary solutions for the slab of five-dimensional AdS spacetime where the fifth dimension is an orbifold $S^1/Z_2$ and two three-branes reside at its boundaries, of which...
Nonthermal Axino as Cool Dark Matter in Supersymmetric Standard Model without R-parity (1999)
We point out that the axino predicted as the supersymmetric partner of the axion is a good candidate for the recently proposed sterile neutrino cool dark matter. The axino mass falls into the right...
Cosmological Gravitino Production in Gauge Mediated Supersymmetry Breaking Models (1999)
Choi, Kiwoon, Hwang, Kyuwan, Kim, Hang Bae, Lee, Taekoon
We study the cosmological gravitino production in gauge mediated supersymmetry breaking models, while properly taking into account the existence of the messenger mass scale. It is found that for...
Moduli Stabilization in Heterotic $M$-theory (1998)
Choi, Kiwoon, Kim, Hang Bae, Kim, Hyungdo
We examine the stabilization of the two typical moduli, the length $\rho$ of the eleventh segment and the volume $V$ of the internal six manifold, in compactified heterotic $M$-theory. It is shown...
Cosmology of Light Moduli (1998)
Choi, Kiwoon, Chun, Eung Jin, Kim, Hang Bae
In string/M-theory with a large compactification radius, some axion-like moduli can be much lighter than the gravitino. Generic moduli in gauge-mediated supersymmetry breaking models also have a mass...
Four-Dimensional Effective Supergravity and Soft Terms in M-Theory (1997)
Choi, Kiwoon, Kim, Hang Bae, Munoz, Carlos
We provide a simple macroscopic analysis of the four-dimensional effective supergravity of the Ho\v{r}ava-Witten M-theory which is expanded in powers of $\kappa^{2/3}/\rho V^{1/3}$ and...
Orbifolds with continuous Wilson lines and soft terms (1996)
Orbifold compactifications with continuous Wilson lines have very interesting characteristics and as a consequence they are candidates to obtain realistic models. We perform an analysis of the soft...
Axion Cosmology with a Stronger QCD in the Early Universe (1996)
Choi, Kiwoon, Kim, Hang Bae, Kim, Jihn E.
We examine in the context of supersymmetric models whether the usual cosmological upper bound on the axion decay constant can be relaxed by assuming a period of stronger QCD in the early universe. By...
A dark matter solution from the supersymmetric axion model (1996)
Chang, Sanghyeon, Kim, Hang Bae
We study the effect of the late decaying saxino (the scalar superpartner of the axion) and find out that there is a possible dark matter solution from a class of supersymmetric extensions of the...
Dark Matter and Structure Formation with Late Decaying Particles (1994)
Since it became evident that the CDM model for cosmic structure formation predicts smaller power on large scales than observed, many alternatives have been suggested. Among them, the existence of...
Dark Matters in Axino Gravitino Cosmology (1993)
Chun, Eung Jin, Kim, Hang Bae, Kim, Jihn E.
It is suggested that the axino mass in the 1 MeV region and gravitino mass in the eV region can provide an axino lifetime of order of the time of photon decoupling. In this case, some undecayed...
Coupling Constant Unification and LEP Data (1993)
The recent LEP data for gauge coupling constants constrain many grand unified models. In this paper, we study several possibilities for unification of gauge coupling constants. Without an...
An Orbifold Compactification with Three Families from Twisted Sectors (1992)
We obtain a three generational $SU(3)_c\times SU(3)_w \times U(1)^4\times [SO(12)\times U(1)^2]^\prime$ model from an orbifold construction with the requirement that three generations arise from...