We consider a supersymmetric hybrid inflation model with two inflaton fields. The superpotential during inflation is dominated by W=(\kappa S + \kappa' S')M^2, where S, S' are the (twin) inflatons...
Decaying LSP in SO(10) GUT and PAMELA's Cosmic Positron (2009)
We suppose that the lightest supersymmetric particle (LSP) in the minimal supersymmetric standard model (MSSM) is dark matter. The bino-like LSP can decay through the SO(10) gauge interactions, if...
SU(5)_{flip} x SU(5)' from Z_{12-I} (2009)
Huh, Ji-Haeng, Kim, Jihn E., Kyae, Bumseok
Based on the Z_{12-I} orbifold compactification of the heterotic string theory, we construct a flipped-SU(5) model with three families of the standard model matter and ingredients for dynamical...
PAMELA/ATIC Anomaly from Exotic Mediated Dark Matter Decay (2009)
We discuss dark matter decay mediated by exotically charged particles ("exotics") in a supersymmetric model with two dark matter (DM) components: One is the (bino-like) lightest supersymmetric...
We present a supersymmetric model with two dark matter (DM) components explaining the galactic positron excess observed by PAMELA/HEAT and ATIC/PPB-BETS: One is the conventional (bino-like) lightest...
The minimal two DM components with SUSY (2008)
Huh, Ji-Haeng, Kim, Jihn E., Kyae, Bumseok
We present the dark matter extension of the minimal supersymmetric standard model by one more two component stable fermion N toward explaining the recent rising high energy positron spectrum of the...
White dwarf axions, PAMELA data, and flipped-SU(5) (2008)
Bae, Kyu Jung, Huh, Ji-Haeng, Kim, Jihn E., Kyae, Bumseok, Viollier, Raoul D.
Recently, there are two hints arising from physics beyond the standard model. One is a possible energy loss mechanism due to emission of very weakly interacting light particles from white dwarf...
Orbifold SUSY GUT from the Heterotic String (2008)
From the string partition function, we discuss the mass-shell and GSO projection conditions valid for Kaluza-Klein (KK) as well as massless states in the heterotic string theory compactified on a...
Huh, Ji-Haeng, Kim, Jihn E., Kyae, Bumseok
We present the dark matter (DM) extension (by N) of the minimal supersymmetric standard model to give the recent trend of the high energy positron spectrum of the PAMELA/HEAT experiments. If the...
Kaluza-Klein masses in nonprime orbifolds: Z(12-I) compactification and threshold correction (2007)
Analyzing the one-loop partition function, we discuss possible Kaluza-Klein (KK) states in the orbifold compactification of the heterotic string theory, toward the application to the threshold...
SO(10)-like Superstring Standard Model with R-parity from the Heterotic String (2007)
Kim, Jihn E., Kim, Ji-Hun, Kyae, Bumseok
We construct a supersymmetric standard model in the context of the Z_{12-I} orbifold compactification of the E_8 x E_8' heterotic string theory. The gauge group is SU(3)_c x SU(2)_L x U(1)_Y x U(1)^4...
Kim, Jihn E., Kim, Ji-Hun, Kyae, Bumseok
We construct a supersymmetric standard model in the context of the $Z_{12-I}$ orbifold compactification of the heterotic string theory. The gauge group is $SU(3)_c\times SU(2)_L\times U(1)_Y\times...
Harmless R-parity violation from Z_{12-I} compactification of E_8 X E_8' heterotic string (2006)
Kim, Ian-Woo, Kim, Jihn E., Kyae, Bumseok
In a recent $\Z_{12-I}$ orbifold model, an approximate $Z_2$ symmetry which forbids the baryon number violating operators up to sufficiently high orders is found. The dimension-4 $\Delta B\ne 0$...
Cosmic D- and DF-strings from D3Dbar3: Black Strings and BPS Limit (2006)
Kim, Taekyung, Kim, Yoonbai, Kyae, Bumseok, Lee, Jungjai
We study D- and DF-strings in a D3${\bar {\rm D}}3$ system by using Dirac-Born-Infeld type action. In the presence of an electric flux from the transverse direction, we discuss gravitating thick...
String MSSM through flipped SU(5) from Z_{12} orbifold (2006)
In a $Z_{12-I}$ orbifold compactification through an intermediate flipped SU(5), the string MSSM (${\cal S}$MSSM) spectra (three families, one pair of Higgs doublets, and neutral singlets) are...
Flipped SU(5) from Z_{12-I} orbifold with Wilson line (2006)
We construct a three family flipped SU(5) model from the heterotic string theory compactified on the $\Z_{12-I}$ orbifold with one Wilson line. The gauge group is $\rm SU(5)\times U(1)_X\times...
Flat-Directions in Grand Unification With $U(1)_R$ Symmetry (2005)
Barr, S. M., Kyae, Bumseok, Shafi, Qaisar
It is shown that in SO(10) and SU(5) models having a $U(1)_R$ symmetry, the requirement of breaking the unified group to the Standard Model leads to flat directions in the scalar potential. These can...
DF-strings from D3${\bar {\bf D}}$3 as Cosmic Strings (2005)
Cho, Inyong, Kim, Yoonbai, Kyae, Bumseok
We study Dirac-Born-Infeld type effective field theory of a complex tachyon and U(1)$\times$U(1) gauge fields describing a D3${\bar {\rm D}}$3 system. Classical solutions of straight global and local...
Inflation With A Realistic SO(10) Model (2005)
We implement inflation within a realistic supersymmetric SO(10) model in which the doublet-triplet splitting is realized through the Dimopoulos-Wilczek mechanism, the MSSM $\mu$ problem is resolved,...
Flipped SU(5) Predicts $\delta T/T$ (2005)
We discuss hybrid inflation in supersymmetric flipped SU(5) model such that the cosmic microwave anisotropy $\delta T/T$ is essentially proportional to $(M /M_{P})^2$, where $M$ denotes the symmetry...
Global and Local D-vortices (2005)
Kim, Yoonbai, Kyae, Bumseok, Lee, Jungjai
Codimension-two objects on a system of brane-antibrane are studied in the context of Born-Infeld type effective field theory with a complex tachyon and U(1)$\times$U(1) gauge fields. When the radial...
Inflation With Realistic Supersymmetric SO(10) (2005)
We implement inflation within a realistic supersymmetric SO(10) model in which the doublet-triplet splitting is realized through the Dimopoulos-Wilczek mechanism, the MSSM $\mu$ problem is resolved,...
Time-varying Quark Masses and Cosmological Axion Energy (2004)
The possibility is examined that the masses of the light quarks $u$ and $d$ have varied over the course of the universe's evolution. Such a variation would have an effect on axion cosmology, and can...
A General Analysis of Corrections to the Standard See-saw Formula in Grand Unified Models (2004)
In realistic grand unified models there are typically extra vectorlike matter multiplets at the GUT scale that are needed to explain the family hierarchy. These contain neutrinos that, when...
$\delta T/T$ and Neutrino Masses in SU(5) (2004)
We implement inflation in a supersymmetric SU(5) model with U(1) R-symmetry such that the cosmic microwave anisotropy $\delta T/T$ is proportional to $(M/M_{\rm Planck})^2$, where $M\sim...
Self-tuning of the cosmological constant and Einstein Gravity on the brane (2004)
Kim, Jihn E., Kyae, Bumseok, Shafi, Qaisar
We show that a self-tuning mechanism of the cosmological constant could work in 5D non-compact space-time. The standard model matter fields live only on the 4D brane. The change of vacuum energy on...
Inflation and Leptogenesis in Five Dimensional SO(10) (2003)
We discuss five dimensional (5D) supersymmetric SO(10) compactified on the orbifold $S^1/(Z_2\times Z_2')$ such that the SO(10) gauge symmetry is broken on the fixed point(s) to its maximal...
Einstein Gravity on a Brane in 5D Non-compact Flat Spacetime -DGP model revisited- (2003)
We revisit the 5D gravity model by Dvali, Gabadadze, and Porrati (DGP). Within their framework it was shown that even in 5D non-compact Minkowski space $(x^\mu,z)$, the Newtonian gravity can emerge...
Low Energy Consequences of Five Dimensional SO(10) (2003)
Kyae, Bumseok, Lee, Chin-Aik, Shafi, Qaisar
We consider five dimensional (5D) supersymmetric SO(10) compactified on the orbifold $S^1/(Z_2\times Z_2')$ such that the SO(10) gauge symmetry is broken on both fixed points (branes), and the...
F-term Inflation and Leptogenesis with 5D SO(10) (2003)
We discuss a five dimensional inflationary scenario based on a supersymmetric SO(10) model compactified on $S^1/(Z_2\times Z_2')$. Inflation is implemented through scalar potentials on four...
Brane gravity, massless bulk scalar and self-tuning of the cosmological constant (2003)
Kim, Jihn E., Kyae, Bumseok, Shafi, Qaisar
We show that a self-tuning mechanism of the cosmological constant could work in 5D non-compact space-time with a $Z_2$ symmetry in the presence of a massless scalar field. The standard model matter...
Grand Unified Inflation Confronts WMAP (2003)
In a class of realistic four and five dimensional supersymmetric grand unified models, the scalar spectral index is found to be $n_s=0.98 (\pm 0.01)$, in excellent agreement with the values...
Inflationary Cosmology with Five Dimensional SO(10) (2002)
We discuss inflationary cosmology in a five dimensional SO(10) model compactified on $S^1/(Z_2\times Z_2')$, which yields $SU(3)_c\times SU(2)_L\times U(1)_Y\times U(1)_X$ below the compactification...
GUT Scale And Leptogenesis From 5D Inflation (2002)
We discuss a five dimensional inflationary scenario based on a supersymmetric SO(10) model compactified on $S^1/(Z_2\times Z_2')$. Inflation is implemented through scalar potentials on four...
A model with bulk and brane gauge kinetic terms and SUSY breaking without hidden sector (2002)
We derive various solutions for the gauge field and the gaugino when there are both 5D bulk kinetic terms and 4D brane kinetic terms. Below the compactification scale $1/y_c$, gauge interaction by...
Non-universal Soft Parameters in Brane World and the Flavor Problem in Supergravity (2002)
We consider gravity mediated supersymmetry (SUSY) breaking in 5D spacetime with two 4D branes B1 and B2 separated in the extra dimension. Using an off-shell 5D supergravity (SUGRA) formalism, we...
Family Unification in Five and Six Dimensions (2002)
Babu, K. S., Barr, S. M., Kyae, Bumseok
In family unification models, all three families of quarks and leptons are grouped together into an irreducible representation of a simple gauge group, thus unifying the Standard Model gauge...
Branes and Inflationary Cosmology (2001)
We discuss a brane based inflationary scenario in which an initially non-supersymmetric configuration involving a D4 brane is dynamically transformed into a supersymmteric one in a background...
Kim, Jihn E., Kyae, Bumseok, Lee, Hyun Min
We consider flat solutions in the brane background with a massless scalar field appearing in 5D $H^2_{MNPQ}$. Since there exist bulk singularities or arises the divergent 4D Planck mass, we should...
Localized gravity and mass hierarchy in D=6 with the Gauss-Bonnet term (2001)
Kim, Jihn E., Kyae, Bumseok, Lee, Hyun Min
We obtain the localized gravity on the intersection of two orthogonal non-solitonic or solitonic 4-branes in D=6 in the presence of the Gauss-Bonnet term. The tension of the intersection is allowed...
Effective supersymmetric theory and muon anomalous magnetic moment with R parity violation (2001)
Kim, Jihn E., Kyae, Bumseok, Lee, Hyun Min
The effective supersymmetric theory (ESUSY) with R parity conservation cannot give a large anomalous magnetic moment of $\mu$. It is pointed out that the flavor conservation and a large $(g-2)_\mu$...
Self-tuning solution of the cosmological constant problem with antisymmetric tensor field (2001)
Kim, Jihn E., Kyae, Bumseok, Lee, Hyun Min
We present a self-tuning solution of the cosmological constant problem with one extra dimension which is curved with a warp factor. To separate out the extra dimension and to have a self-tuning...
Cosmology and Modulus Stabilization in the Randall-Sundrum Setup with Bulk Matter (2000)
We provide the exact time-dependent cosmological solutions in the Randall-Sundrum (RS) setup with bulk matter, which may be smoothly connected to the static RS metric. In the static limit of the...
Model for self-tuning the cosmological constant (2000)
Kim, Jihn E., Kyae, Bumseok, Lee, Hyun Min
The vanishing cosmological constant in the four dimensional space-time is obtained in a 5D Randall-Sundrum model with a brane (B1) located at $y=0$. The matter fields can be located at the brane. For...
The $\mu$ and soft masses from the intermediate scale brane with non-factorizable geometry (2000)
The proton decay problem and the negative brane tension problem in the original Randall-Sundrum model can be resolved by interpreting the Planck scale brane as the visible sector brane. The hierarchy...
The radion contribution to the weak mixing angle (2000)
Kim, Jihn E., Kyae, Bumseok, Park, Jong Dae
In the Randall-Sundrum (RS) compactification, the gap between two branes is stabilized by the vacuum expectation value of a scalar field called {\it radion}, $\phi$. This radion behaves like a weak...
We provide the exact time-dependent cosmological solutions in the Randall-Sundrum (RS) setup with bulk matter, which may be smoothly connected to the static RS metric. In the static limit of the...
Various Modified Solutions of the Randall-Sundrum Model with the Gauss-Bonnet Interaction (2000)
Kim, Jihn E., Kyae, Bumseok, Lee, Hyun Min
The Gauss-Bonnet interaction is the only consistent quadratic interaction below the Planck scale in the Randall-Sundrum compactification. We study various static and inflationary solutions including...
Effective Gauss-Bonnet Interaction in Randall-Sundrum Compactification (1999)
Kim, Jihn E., Kyae, Bumseok, Lee, Hyun Min
The effective gravitational interaction below the Planck scale in the Randall-Sundrum world is shown to be the Gauss-Bonnet term. In this theory we find that there exists another static solution with...
Constraints on Parameters of the R_F Parity Model from Quark and Neutrino Mass Matrices (1999)
Kim, Jihn E., Kyae, Bumseok, Lee, Jae Sik
The forms of quark and lepton mass matrices are severely restricted in the $R_F$ parity model. We determine the form of the quark mass matrix first and derive the form of the neutrino mass matrix....
R_F Parity and Almost Massless Up Quark (1998)
Kim, Jihn E., Kyae, Bumseok, Lee, Jae Sik
We introduce a parity $R_F$ to introduce naturally small masses for the first family members and in particular almost massless $u$ quark toward the strong CP solution. We also discuss the...
Large Cosmological Light Element Bound on R Parity Violating Parameters (1998)
Kim, Jihn E., Kyae, Bumseok, Park, Jong Dae
In R parity violating theories, there does not exist the {\it stable} lightest supersymmetric particle (LSP). The LSP, $\chi$, of MSSM decays to lighter ordinary particles with dimension 6 effective...