Right-handed sneutrino dark matter in the NMSSM (2009)
Cerdeno, David G., Seto, Osamu
We study the properties of the right-handed sneutrino and its viability as a WIMP dark matter candidate in an extended version of the NMSSM in which a right-handed neutrino superfield is included...
A TeV scale model for neutrino mass, dark matter and baryon asymmetry (2009)
Aoki, Mayumi, Kanemura, Shinya, Seto, Osamu
We discuss a TeV scale model which would explain neutrino oscillation, dark matter, and baryon asymmetry of the Universe simultaneously by the dynamics of the extended Higgs sector and TeV-scale...
Aoki, Mayumi, Kanemura, Shinya, Seto, Osamu
We discuss some details for the model proposed in Ref. \cite{aks-prl}, in which neutrino oscillation, dark matter, and baryon asymmetry of the Universe can be simultaneously explained by the...
Right-handed sneutrino dark matter in the NMSSM (2009)
Cerdeno, David G., Seto, Osamu
We study the properties of the right-handed sneutrino and its viability as a WIMP dark matter candidate in an extended version of the NMSSM in which a right-handed neutrino superfield is included...
An extended Higgs sector for neutrino mass, dark matter and baryon asymmetry (2009)
Aoki, Mayumi, Kanemura, Shinya, Seto, Osamu
In this talk, we discuss a TeV scale model which would explain neutrino oscillation, dark matter, and baryon asymmetry of the Universe simultaneously by the dynamics of the extended Higgs sector and...
A TeV-scale model for neutrino mass, DM and baryon asymmetry (2009)
Aoki, Mayumi, Kanemura, Shinya, Seto, Osamu
We discuss a model which would explain neutrino oscillation, dark matter, and baryon asymmetry of the Universe simultaneously by the physics at TeV scales. Tiny neutrino masses are generated at the...
Right-handed sneutrino as thermal dark matter (2008)
Cerdeño, David G., Muñoz, Carlos, Seto, Osamu
4 pages, 2 figures.
Neutrino mass, Dark Matter and Baryon Asymmetry via TeV-Scale Physics without Fine-Tuning (2008)
Aoki, Mayumi, Kanemura, Shinya, Seto, Osamu
PACS numbers: 14.60.Pq, 14.60.St, 14.80.Cp, 12.60.Fr.-- 4 pages including 3 figures.
Neutrino mass, Dark Matter and Baryon Asymmetry via TeV-Scale Physics without Fine-Tuning (2008)
Aoki, Mayumi, Kanemura, Shinya, Seto, Osamu
We propose an extended version of the standard model, in which neutrino oscillation, dark matter, and baryon asymmetry of the Universe can be simultaneously explained by the TeV-scale physics without...
Supersymmetric inflation and baryogenesis via Extra-Flat directions of the MSSM. (2008)
One interpretation of proton stability is that it implies the existence of extra-flat directions of the minimal supersymmetric standard model, in particular ucucdcec and QQQL, where the operators...
Neutralino dark matter from heavy axino decay (2008)
Choi, Ki-Young, Kim, Jihn E., Lee, Hyun Min, Seto, Osamu
Submitted on 3 Jan 2008 (v1), last revised 19 Jun 2008 (this version, v2).-- 7 pages, 4 figures; references added, published version in Phys. Rev. D.-- PACS numbers: 95.35.+d, 98.80.Cq.
Non-perturbative moduli superpotential with positive exponents (2008)
Abe, Hiroyuki, Higaki, Tetsutaro, Kobayashi, Tatsuo, Seto, Osamu
Submitted on 21 Apr 2008 (v1), last revised 24 Apr 2008 (this version, v2).-- 13 pages, 4 figures.-- v2: reference added.
Non-perturbative moduli superpotential with positive exponents (2008)
Abe, Hiroyuki, Higaki, Tetsutaro, Kobayashi, Tatsuo, Seto, Osamu
We study non-perturbative moduli superpotentials with positive exponents, i.e. the form like $Ae^{aT}$ with a positive constant $a$ and the modulus $T$. These effects can be generated, e.g., by...
Sterile right-handed neutrinos can be naturally embedded in a low scale gauged $U(1)_{B-L}$ extension of the standard model. We show that, within a low reheating scenario, such a neutrino is an...
Sterile neutrino dark matter in B-L extension of the standard model and galactic 511 keV line (2008)
PACS numbers: 95.35.+d, 13.15.+g, 98.80.Cq, 98.70.Rz.-- 10 pages, 1 figure.
Supersymmetric inflation and baryogenesis via Extra-Flat directions of the MSSM (2008)
One interpretation of proton stability is the existence of extra-flat directions of the MSSM, in particular $u^{c}u^{c}d^{c}e^{c}$ and $QQQL$, where the operators lifting the potential are suppressed...
Neutralino dark matter from heavy axino decay (2008)
Choi, Ki-Young, Kim, Jihn E., Lee, Hyun Min, Seto, Osamu
We consider cosmological consequences of a heavy axino, decaying to the neutralino in R-parity conserving models. The importance and influence of the axino decay on the resultant abundance of...
Gravitino dark matter from increased thermal relic particles (2007)
We investigate the so-called superWIMP scenario with gravitino as the lightest supersymmetric particle (LSP) in the context of non-standard cosmology, in particular, brane world cosmology. As a...
Dynamical solutions of warped six dimensional supergravity (2007)
Copeland, Edmund J., Seto, Osamu
We derive a new class of exact time dependent solutions in a warped six dimensional supergravity model. Under the assumptions we make for the form of the underlying moduli fields, we show that the...
Axino warm dark matter and $\Omega_b - \Omega_{DM}$ coincidence (2007)
Seto, Osamu, Yamaguchi, Masahide
We show that axinos, which are dominantly generated by the decay of the next-to-lightest supersymmetric particles produced from the leptonic $Q$-ball ($L$-ball), become warm dark matter suitable for...
Roszkowski, Leszek, Seto, Osamu
We show that the $\Omega_b - \Omega_{DM}$ coincidence can naturally be explained in a framework where axino cold dark matter is predominantly produced in non-thermal processes involving decays of...
Affleck-Dine baryogenesis and gravitino dark matter (2005)
Affleck-Dine baryogenesis in models where the gravitino is both the lightest supersymmetric particle and the dark matter candidate is investigated. For a high enough reheating temperature to produce...
Light wino dark matter in brane world cosmology (2005)
Nihei, Takeshi, Okada, Nobuchika, Seto, Osamu
The thermal relic density of the wino-like neutralino dark matter in the brane world cosmology is studied. The expansion law at a high energy regime in the brane world cosmology is modified from the...
Hiding cosmic strings in supergravity D-term inflation (2005)
Seto, Osamu, Yokoyama, Jun'ichi
The influence of higher-order terms in the K\"{a}hler potential of the supergravity D-term inflation model on the density perturbation is studied. We show that these terms can make the inflaton...
Thermal leptogenesis in brane world cosmology (2005)
The thermal leptogenesis in brane world cosmology is studied. In brane world cosmology, the expansion law is modified from the four-dimensional standard cosmological one at high temperature regime in...
Reheating and gravitino production in braneworld inflation (2005)
Copeland, Edmund J., Seto, Osamu
We consider the constraints that can be imposed on a wide class of Inflation models in modified gravity scenarios in which the Friedmann equation is modified by the inclusion of $\rho^2$ terms, where...
Neutralino dark matter in brane world cosmology (2004)
Nihei, Takeshi, Okada, Nobuchika, Seto, Osamu
The thermal relic density of the neutralino dark matter in the brane world cosmology is studied. Since the expansion law at a high energy regime in the brane world cosmology is modified from the one...
The Effect of Extra Dimension on Dark Matter (2004)
We investigate the thermal relic density of a cold dark matter in the brane world cosmology. Since the expansion law in a high energy regime is modified from the one in the standard cosmology, if the...
A brane world cosmological solution to the gravitino problem (2004)
We investigate the thermal production of gravitinos in the context of the brane world cosmology. Since the expansion law is modified from the one in the standard cosmology, the Boltzmann equation for...
Relic density of dark matter in brane world cosmology (2004)
We investigate the thermal relic density of the cold dark matter in the context of the brane world cosmology. Since the expansion law in a high energy regime is modified from the one in the standard...
Phenomenology of TeV Right-handed Neutrino and the Dark Matter Model (2004)
In a model of TeV right-handed (RH) neutrino by Krauss, Nasri, and Trodden, the sub-eV scale neutrino masses are generated via a 3-loop diagram with the vanishing see-saw mass forbidden by a discrete...
D-term Inflation and Nonperturbative Kahler Potential of Dilaton (2004)
Higaki, Tetsutaro, Kobayashi, Tatsuo, Seto, Osamu
We study the $D$-term inflation scenario with a nonperturbative K\"ahler potential of the dilaton field. Although the FI term which leads an inflationary expansion is given by the derivative of the...
Dilaton and Moduli Fields in D-term inflation (2003)
Kobayashi, Tatsuo, Seto, Osamu
We investigate the possibility of $D$-term inflation within the framework of type I string-inspired models. Although $D$-term inflation model has the excellent property that it is free from the...
Stabilizing dilaton and baryogenesis (2002)
Dolgov, Alexander D., Kohri, K., Seto, Osamu, Yokoyama, Jun'ichi
Entropy production by the dilaton decay is studied in the model where the dilaton acquires potential via gaugino condensation in the hidden gauge group. Its effect on the Affleck-Dine baryogenesis is...
Oscillating scalar-field dark matter in supergravity (2001)
Seto, Osamu, Kohri, K., Nakamura, Takashi
We show that an oscillating scalar field in supergravity of mass of the order of $\sim$ TeV with a nonzero vacuum expectation value ($\sim 10^{10}$ GeV) can be a candidate of cold dark matter (CDM)....
Gravitational waves in cosmological models of Ho\v{r}ava-Witten theory (2000)
We study the behavior of gravitational waves and their backreaction on the background in cosmological solutions of the five-dimensional Ho\v{r}ava-Witten theory. As a dynamical background, we...
Brane World Cosmology - Gauge-Invariant Formalism for Perturbation (2000)
Kodama, Hideo, Ishibashi, Akihiro, Seto, Osamu
In the present paper the gauge-invariant formalism is developed for perturbations of the brane-world model in which our universe is realized as a boundary of a higher-dimensional spacetime. For the...
What happens when the inflaton stops during inflation (1999)
Seto, Osamu, Yokoyama, Jun'ichi, Kodama, Hideo
The spectrum of adiabatic density perturbation generated during inflation is studied in the case the time derivative of an inflation-driving scalar field (inflaton) vanishes at some time during...