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1 Cai, R. G. ; Ohta, N. (Graduate School of Science)
Bekenstein Bound, Holography and Brane Cosmology in Charged Black Hole Background
Classical and Quantum Gravity, 18, 5429-5440 (2001)

One of the most important problems in theoretical physics is how to understand black hole entropy in quantum theory of gravity. In this paper, using the correspondence of anti-de Sitter space-time and conformal field theory suggested by superstring, we derive the upper bound on the entropy for charged black holes in arbitrary dimensions. This result clarifies that we can address the entropy problems in the framework of field theories. We also discuss holographic properties of various models of brane cosmology.

2 Fujiwara, A. (Graduate School of Science)
Quantum Birthday Problems: Geometrical Aspects of Quantum Random Coding
IEEE Transactions on Information Theory, 47, 2644-2649 (2001)

This paper explores asymptotics of randomly generated vectors on extended Hilbert spaces. In particular, we are interested to know how "orthogonal" these vectors are. We investigate two kinds of asymptotic orthogonality: the weak orthogonality and the strong orthogonality. As regards the weak orthogonality, a new characterization of the von Neumann entropy is derived, and a mechanism behind the noiseless quantum channel coding theorem is clarified. As regards the strong orthogonality, on the other hand, a characterization of the quantum Rényi entropy of degree 2 is derived.

3 Ibukiyama, T. ; Saito, H. (Graduate School of Science)
On "Easy" Zeta Functions
Sugaku Exposition, 14, 191-204(2001)

Zeta functions are often important basic tools for number theory.Here we show that, contrary to the common belief before, zeta functions of some important class of prehomogeneous vector spaces are unexpectedly easy objects described by already known functions. We also propose a notion of new class f "easy" zeta functions who have no Euler products, and suggest a new area of the theory. As an application, we give explicit conjectural dimension formulas for Siegel modular forms of any degree.

4 Imura, K. ; Kawashima, T.; Ohoyama, H. ; Kasai, T. (Graduate School of Sciene)
Direct Determination of the Permanent Dipole Moments and Structures of Al-CH3CN and Al-NH3 by Using a 2-m Electrostatic Hexapole Field
Journal of The American Chemical Society, 123, 6367-6371 (2001)

The supersonic beams of pure metal-ligand (1-1) complexes of Al-NH3 and Al-CH3CN are synthesized in laser evaporation flow-tube-reactor, and they are non-destructively structure-selected by 2-meter long electrostatic hexapole state-selector for the first time. We experimentally find that the permanent dipole moment of Al-NH3(2.7 D) is larger than NH3, while that of Al-CH3CN(1.2 D) is smaller than CH3CN. The ab initio calculations clarify that competition of "charge transfer" and "polarization" effects through metal-ligand bond play a key role.

5 Ishikawa, A. ; Ogawa, T. (Graduate School of Science)
Dynamics of Spinodal Decomposition in Finite-Lifetime Systems: Nonlinear Statistical Theory Based on a Coarse-Grained Lattice-Gas Model
Physical Review E, 65, 026131 (2002)

Dynamics of the spinodal decomposition in finite-lifetime systems is theoretically investigated to clarify effects of interparticle interactions on photoexcited high-density electron-hole systems. We employ the coarse-grained lattice-gas model to derive coupled integrodifferential equations for the single-point distribution function and the structure factor. (i) The finite lifetime prevents the phase separation under the continual excitation. Domains cannot grow to be larger than an asymptotic size L. (ii) Power-law dependence of L on the interaction and the lifetime is also found.

6 Kato, R. ; Kataoka, M. ; Kamikubo, H. ; Kuramitsu S. (Graduate School of Science)
Direct Observation of Three Conformations of MutS Protein Regulated by Adenine Nucleotides
Journal of Molecular Biology, 309, 227-238(2001)

Mismatched base-pairs, which are caused by either DNA replication errors, DNA damage or genetic recombination, are repaired by the DNA mismatch-repair system. This repair system is essential for all living organisms including human, and the MutS protein recognizes mismatched base-pairs, constituting the first step of the DNA mismatch-repair system. The MutS protein from Thermus thermophilus HB8 was studied by small-angle X-ray scattering, and was found to exist in three different conformations in solution depending on the absence or presence of ATP/ADP.

7 Kawakami, T.*1 ; Nasu, S.*1 ; Sasaki, T.*1 ; Kuzushita, K.*1 ;
Morimoto, S.
*1 ; Endo, S.*2 ; Yamada, T. ; Kawasaki, S. ; Takano, M.
*1(Graduate School of Engineering Science) *2( Research Center for Materials Science at Extreme Conditions)
Pressure-Induced Transition from a Charge-Disproportionated Antiferromagnetic State to a Charge-Uniform Ferromagnetic State in Sr 2 of 3 La 1 of 3 FeO3
Physical Review Letters, 88, 037602(1)-037602(4) (2002)

8 Kodama, R.*1 ; Norreys, P. A. ; Mima, K.*1 ; Dangor, A. E. ; Evans, R. G ; Fujita, H.*1 ; Kitagawa, Y.*1 ; Krushelnick, K. ; Miyakoshi T.*1;
Miyanaga N.*1 ; Norimatsu T.*1; Rose, S. J. ; Shozaki T.*1 ;
Shigemori, K.*1 ; Sunahara, A.*1 ; Tampo, M.*1 ; Tanaka, K.*2 ;
Toyama Y.*1 ; Yamanaka, T.*1 ; Zepfy, M.
*1(Institute of Laser Engineering) *2(Graduate School of Engineering)
Fast Heating of Ultrahigh-density Plasma as a Step towards Laser Fusion Ignition
Nature, 412, 798-802 (2001)

9 Kohno, H. ; Takeda, S. (Graduate School of Science)
Silicon Nanoneedles Grown by a Simple Thermal Treatment Using Metal-Sulfur Catalysts
Japanese Journal of Applied Physics, 41, 577-578 (2002)

10  Kohri, H. ; Ajimura, S. ; Hayakawa, H. ; Kishimoto, T. ;
Matsuoka, K.
; Minami, S. ; Miyake, Y. ; Mori, T. ; Morikubo, K. ; Saji, E. ; Sakaguchi, A. ; Shimizu, Y. ; Sumihama, M. ; Chrien, R. E. ; May M. ; Pile, P. ; Rusek, A. ; Sutter, R. ; Eugenio, P. M. ; Franklin, G. ;
Khaustov, P. ; Paschke, K. ; Quinn, B. P. ; Schumacher, R. ; Franz, J. ; Fukuda, T. ; Noumi, H. ; Outa, H. ; Gan, L. ; Tang, L. ; Yuan L. ; Nakano, J. ; Tamagawa, T. ; Tanida, K. ; Sawafta, R. ; Tamura, H. ; Akikawa, H. (Graduate School of Science)
13ΛC Hypernucleus Studied with the 13C(K-,π-γ) Reaction
Physical Review C, 65, 034607(1)-034607(9)(2002)

The structure of the 13ΛC hypernucleus was successfully studied by the γ-ray spectroscopy with the K- induced π- production reaction on a 13C target. The fine energy resolution of the γ-ray spectroscopy enabled us to determine the level energies of the hypernucleus with about 10 times better accuracy than that of previous measurements. The information on the level structure helped us to understand the effective interactions, especially the spin-dependent interactions, between a Λ hyperon and a nucleus.
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