Seminars

2010

Report Meeting by GCOE Postdocs
Date and time
March 7th, 2010 (Mon) pm: 13:20 - 16:20
Place
Room 525 [5F], Physics Department)
Program
13:20 Kazuto Otani
Efficient laser-proton acceleration from locally metal coated polyethylene foil
13:40 Shigeto Kabuki
Study of 3D Reconstruction Method for Electron-Tracking Compton Camera
14:00 Ryo Toda
A role of 3He atoms for NCRI response of solid 4He
14:20 Norichika Sago
Cross-cultural comparison between black hole perturbation and post-Newtonian theory
14:40 Break
15:00 Naoki Isobe
Longterm X-ray observation of blazars with MAXI
15:20 Hidetoshi Morita
Spatio-temporal pattern in a conservative dynamical system
15:40 Yoshimasa Hidaka
Soft modes in QED/QCD plasma at high temperature
16:00 Alberto Martinez Torres
Few-body systems made of kaons
GCOE/YITP seminar
title
Experimental investigations in superconductor/ferromagnet heterostructues: a close look to induced superconductivity inside a ferromagnet
author
Professor Edgar Patino
(University of Los Andes, Bogota, Colombia)
date
Feb. 8 (TUE), 2011, 13:30 - 14:45
place
Room 525[5F], Physics Department
abstract
 This talk starts with a short review of the main experimental investigations on the title subject. It is also intended to serve as an introduction to the physics of superconductivity under the presence of domain walls. First, the speaker briefly discusses general aspects of Superconductor/Ferromagnet (S/F) proximity effects. Then the so-called domain wall superconductivity (DWS) and stray field effects (SFE) are clarified. The talk concludes with a discussion of induced superconductivity inside a ferromagnet, as well as some outstanding issues and desirable future work.
Ref. E. J. Patino, C. Bell and M.G. Blamire,
“Sudden Critical Current Drops Induced in S/F Structures”, European Physical Journal B 68, 73-77 (2009).
contact
Y. Maeno、ext. 3783
note
GCOE/YITP seminar
title
General Many Body Theory for alpha Particle (quartet) condensation in the macroscopic Limit
author
Peter Schuck
(Orsay, France)
date
November 29 (Mon), 2010, 13:30 〜17:30
place
Room 525[5F], Physics Department
abstract
Buffer gas cooling has provided the basis for new types of cold beams, trapping of exotic atoms, study of new collisional processes in atoms and molecules, production of quantum gases and, now, the study of molecule clustering. This talk will review some of the recent results from our lab. This will include the creation of cold molecular beams in a cryogenic intermediate regime where radicals and other species can be formed at temperatures around one Kelvin at a velocity around 150 meters per second. Also presented will be new results on three body and two body association of atoms and molecules. In particular, the binding, or lack thereof, of helium to target species, both atoms and molecules, will be discussed. Cooling of Naphthalene to around four Kelvin will be described.
contact
Yoshiro Takahashi (Ext. 3745) (yitk@scphys.kyoto-u.ac.jp)
note
GCOE Seminar
title
Cooling of Molecules with Inert Gases: from Oxygen to Naphthalene
author
Prof. John M.Doyle
(Harvard University)
date
November 11 (Thu), 2010, 16:00 〜17:30
place
Room 525[5F], Physics Department
abstract
Buffer gas cooling has provided the basis for new types of cold beams, trapping of exotic atoms, study of new collisional processes in atoms and molecules, production of quantum gases and, now, the study of molecule clustering. This talk will review some of the recent results from our lab. This will include the creation of cold molecular beams in a cryogenic intermediate regime where radicals and other species can be formed at temperatures around one Kelvin at a velocity around 150 meters per second. Also presented will be new results on three body and two body association of atoms and molecules. In particular, the binding, or lack thereof, of helium to target species, both atoms and molecules, will be discussed. Cooling of Naphthalene to around four Kelvin will be described.
contact
Yoshiro Takahashi (Ext. 3745) (yitk@scphys.kyoto-u.ac.jp)
note
GCOE/YITP seminar (Particle Physics)
title
Lattice string field theory
author
Michael Kroyter
(Tel-Aviv University)
date
October 25(Mon), 2010, 13:30 -
place
Coference Room Y306, Yukawa Hall, Yukawa Institute, Kyoto University
abstract
 String field theory is a candidate for a full non-perturbative definition of string theory. We want to check whether it might be possible to fully define it at the quantum level. To that end, we try to formulate it on a space-time lattice. We examine potential problems with this approach and then turn to the particular case of one dimensional open bosonic string field theory. We report the first results of our simulations.
contact
Naoki Sasakura ( ext. 7037)
note
http://www.yukawa.kyoto-u.ac.jp/contents/seminar/detail.php?SNUM=51071
GCOE seminar 
title
Solid state physics with fermionic atomic quantum gases: engineering metals and Mott insulators in an optical lattice
author
Dr. Robert Jordens
(ETH Zurich, Prof. Esslinger Group)
date
Sep.28(Tue), 2010, 10:30 〜
place
Room 115[1F], Physics Department
abstract
contact
Yoshiro Takahashi (yitk@scphys.kyoto-u.ac.jp, ext. 3745)
note
GCOE seminar 
title
Towards Magnetic Trapping of CaH
author
Julia H. Rasmussen
(Harvard University, USA)
date
September 17(FRI), 2010, 14:00 - 15:00
place
Room 115[1F], Physics Department
abstract
contact
Yoshiro Takahashi (yitk@scphys.kyoto-u.ac.jp, ext. 3745)
note
GCOE seminar 
title
The ACME Electron EDM Experiment
author
Nicholas R. Hutzler
(Harvard University, USA)
date
September 17(FRI), 2010, 15:30 - 16:30
place
Room 115[1F], Physics Department
abstract
contact
Yoshiro Takahashi (yitk@scphys.kyoto-u.ac.jp, ext. 3745)
note
GCOE seminar/Particle Physics Seminar
title
Thermal effect on the Q-balls and gravitational waves
author
Kohei Kamada
(Reserch Center for the Early Universe, Univ. of Tokyo)
date
July 28, 2010, Wednesday 1:30pm−
place
Conference Room Y206, Yukawa Hall, Yukawa Institute, Kyoto University
abstract
Q-ball formation associated with the Affleck-DIne (AD) mechanism is one of the interesting features of the MSSM flat direction. In particular, when we consider the thermal effect, there emereges a variety of scenarios of the AD mechanism and the Q-ball formation. In this talk, I will show how thermal plasma affects the dynamics of the MSSM flat direction and Q-ball properties. I also explain the cosmological consequences of such features, especially the emission of the gravitational waves and their detectability.
contact
Naoki Sasakura, Yukawa Institute(ext 7037)
note
http://www.yukawa.kyoto-u.ac.jp/contents/seminar/detail.php?SNUM=51049
GCOE seminar
title
Key Symmetries of Superconductivity: Inversion and Time Reversal Symmetry
author
Professor Manfred Sigrist
(ETH Institute for Theoretical Physics, Switzerland)
date
July 16th (FRI), 2010, 16:00 -
place
The 4th Lecture Hall (Room 525) [5F], Physics Department
abstract
Symmetries play an important role for superconductivity. At the superconducting phase transition U(1)-gauge symmetry is spontaneously broken and in so-called unconventional superconductors even further symmetries may be violated which give rise to extraordinary phenomena. Besides this phenomenological symmetry concept there is also the microscopic point of view that superconductivity is based on the formation of Cooper pairs built of degenerate electronic states very close to the Fermi surface. The availability of such degenerate electronic states relies on two key symmetries, inversion and time reversal symmetry, which allow for the most basic classification of superconductors into even-parity (spin singlet) and odd-parity (spin-triplet) pairing. The absence of any of these two symmetries yields a modification of the Cooper pairing states with numerous implications. This presentation will shed light some of the physical properties resulting from the lack of time reversal and inversion symmetry and discusses examples, which we encounter among ferromagnetic and non-centrosymmetric superconductors. Special attention will be given to the later class in the light of recent remarkable developments for the non-centrosymmetric heavy Fermion superconductors.
contact
Yoshiteru Maeno, maeno@scphys.kyoto-u.ac.jp, ext.3783
note
GCOE seminar
title
The Measure of the Universe A Crisis For Cosmology
author
Professor George Efstathiou
(Kavli Institute for Cosmology Cambridge and Institute of Astronomy)
date
June 30 (Wed), 2008, 16:45 - 18:00
place
Room 301, the 6th building of Faculty of Science
abstract
Recent developments in Cosmology and Theoretical Physics suggests that our Universe is just one pocket in a Multiverse, possibly consisting of an infinite number of infinite Universes. Furthermore, astronomical observations have shown, to the surprise of most cosmologists, that the expansion of our Universe is accelerating, rather than decelerating under the action of gravity. This acceleration requires a small, but non-zero, vacuum energy that is 120 orders of magnitude smaller than predicted by fundamental physics. The existence of a Multiverse may explain this puzzle, but a consistent cosmology requires an understanding of how to tame infinities in the Multiverse. This is the `Measure Problem'. Without a solution to this problem, modern cosmology has boxed itself into a crisis.
contact
Misao Sasaki, misao@yukawa.kyoto-u.ac.jp
note
GCOE/YITP Seminar (Condensed Matter physics and Nuclear physics)
title
RG derivation of relativistic fluiddynamic equations for a viscous fluid
author
Teiji Kunihiro
(Kyoto University)
date
22 April, 2010 (Thu) pm 13:30−
place
Panasonic Auditorium, Yukawa Hall, YITP, Kyoto University
abstract
After a brief introduction to the fundamental issues on the theory of relativistic fluid dynamic equations for a viscous fluid, we present an attempt to derive relativistic fluiddynamic equations in general local rest frames for a viscous fluid from the underlying relativistic Boltzmann equation. Our method is based on the so called renormalization-group method as a powerful reduction method of a dynamical system.
The local rest frames (LRF's) are specified by introducing a macroscopic frame vector: The derived first-order equations include the Landau equation in the energy frame as a special case, but the equation in the particle frame does not coincide with the Eckart one which is known to have a pathological property that the thermal equilibrium becomes unstable if the linear perturbation around the equilibrium is described by this equation. We show that our equation has no such a pathological property, and discuss the origin of the difference between the two equations in the particle frame: The dissipative part of the energy-momentum tensor $\delta T^{\mu\nu} $ in the particle frame satisfies $\delta T^\mu_\mu = 0$ , in contrast to the Eckart choice $u_\mu \delta T^{\mu\nu} u_\nu = 0$ adopted as a matching condition by Eckart and the subsequent literature. We emphasize that the way how to impose the matching condition is a fundamentl but has been an unsolved problem. This problem is solved in a natural way by the introduction of the macroscopic frame vector in our method.
In the final part, we briefly present a derivation of the second-order (Israel-Stewart type) dissipative relativistic fluiddynamic equations in a generic frame from the relativistic Boltzmann equation. The relaxation terms in the energy and particle frames are given. Our results show that the viscosities are frame-independent but the relaxation times are generically frame-dependent.
We confirm that the dissipative part of the energy-momentum tensor in the particle frame satisfies $\delta T^\mu_\mu = 0$ obtained for the first-order equation. We show that the new constraint $\delta T^\mu_\mu = 0$ can be compatible with the phenomenological derivation of hydrodynamics based on the second law of thermodynamics.
contact
note
GCOE/YITP seminar(Astrophysics)
title
Phenomenological Aspects of Bounce Cosmology
author
Yifu Cai
(Institute of High Energy Physics, Chinese Academy of Sciences)
date
April 20, 2010 (Tue) 16:00−
place
Conference Room K202, Yukawa Institute, Kyoto University
abstract
In the talk, I will first introduce the singularity problem in current paradigm of cosmology. Up to now, we have no idea of solving this problem in current framework of theoretical physics. However, we have opportunities to study potential observational signals of solutions to cosmic singularities by virtue of effective field theory. I will present two examples to illustrate the big bang singularity can be replaced by a big bounce. I will also talk about the perturbation theory in bounce cosmology, and show that it predicts sizable and negative non-gaussianities which can be measured by near future observations.
contact
note
http://www.yukawa.kyoto-u.ac.jp/contents/seminar/detail.php?SNUM=50977
GCOE/YITP seminar (Nuclear physics)
title
Three-body hadron resonances
author
Alberto Martinez Torres
(YITP, Kyoto University)
date
April 14, 2010 (Wed) 15:00−
place
Conference Room K206, Yukawa Institute, Kyoto University
abstract
We have solved the Faddeev equations for different three-body hadron systems by using as input the two-body chiral t-matrices obtained after solving the Bethe-Salpeter equations in a coupled channel formalism. We have found several resonances in which the three-body interaction is essential in order to describe its properties.
contact
note
http://www.yukawa.kyoto-u.ac.jp/contents/seminar/detail.php?SNUM=50978

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