David Kubiznak, Perimeter Institute
P-V criticality of AdS black holes
Seminar room, Kenkyu honkan 3F
Treating the cosmological constant as a thermodynamic pressure and its conjugate quantity as thermodynamic volume, we reconsider the critical behavior of AdS black holes. We complete the analogy between the thermodynamics of charged AdS black holes and that of the liquid/gas system. The corresponding critical point occurs at a point of divergence of specific heat at constant pressure and is characterized by critical exponents that coincide with those of the Van der Waals fluid. For more complicated black holes, phenomena like reentrant phase transitions, triple points, and even that of the isolated critical points are observed.
Koutarou Kyutoku, RIKEN iTHES
Dynamical mass ejection from black hole-neutron star binaries
Seminar room, Kenkyu honkan 3F In recent years, mass ejection from compact binary coalescences has been getting a lot more attention. Neutron-rich material ejected from neutron stars during such a coalescence event are increasingly recognized as the most promising site of the rapid-process (r-process) nucleosynthesis. Mass ejection will also be the primary agent driving electromagnetic radiation from compact binary mergers, or electromagnetic counterparts to gravitational waves.
In recent years, mass ejection from compact binary coalescences has been getting a lot more attention. Neutron-rich material ejected from neutron stars during such a coalescence event are increasingly recognized as the most promising site of the rapid-process (r-process) nucleosynthesis. Mass ejection will also be the primary agent driving electromagnetic radiation from compact binary mergers, or electromagnetic counterparts to gravitational waves.
Simultaneous detection of electromagnetic counterparts with gravitational waves is eagerly desired, particularly for accurate source localization. Because mass ejection from black hole-neutorn star binaries are violent phenomena involving disruption of neutron stars, numerical relativity is the only reliable approach for theoretical investigation. In this talk, we present our latest results for dynamical mass ejection from the black hole-neutron star binary merger obtained by numerical-relativity simulations.
We also discuss possible electromagnetic counterparts from the anisotropic dynamical ejecta from black hole-neutron star binaries.
Chong-Sun Chu, National Tsing Hua University, Taiwan
On the gravitational loop effects on the cosmological constant
Meeting Room 1, Kenkyu Honkan 1F
In this talk I will consider a 4 dimensional model where the infrared effect at one loop of the graviton provides a screening on the cosmological constant
Michael E. Peskin, SLAC
Secrets of the Higgs Boson
Meeting room 1, Kenkyu honkan 1F
In two and a half years since the discovery of the Higgs boson, many particle physicists have gone the whole route from skepticism about the existence of this particle to contentment with its Standard-Model-like properties. In reality, we have hardly begun to explore the secrets of the Higgs boson. In this lecture, I will review the coming program of precision measurement of the Higgs boson properties. I will discuss the level of precision needed in this study to test theoretical models, the prospects for high-precision theoretical calculation of the Standard Model reference values, and the prospects for high-precision measurements at the LHC and the ILC.
George Zoupanos, National Technical U
Reduction of Couplings in Quantum Field Theories with applications in Finite Theories and the MSSM
Meeting Room 1, Kenkyu Honkan 1F
We apply the method of reduction of couplings in a Finite Unified Theory (FUT) and in the MSSM. The method consists on searching for renormalization group invariant relations among couplings of a renormalizable theory holding to all orders in perturbation theory. It has a remarkable predictive power since, at the unication scale, it leads to relations between gauge and Yukawa couplings in the dimensionless sectors and relations involving the trilinear terms and the Yukawa couplings, as well as a sum rule among the scalar masses and the unified gaugino mass in the soft breaking sector. In both the MSSM and the FUT model we predict the masses of the top and bottom quarks and the light Higgs in remarkable agreement with the experiment. Furthermore we also predict the masses of the other Higgses, as well as the supersymmetric spectrum, both being in very comfortable agreement with the LHC bounds on Higgs and supersymmetric particles.
Markus Rummel, U Oxford
Dark Matter and Dark Radiation from Axion-Like-Particles
Meeting room 3, Kenkyu honkan 1F
First, we discuss the possibility of explaining the 3.5 keV line through dark matter decaying to axion-like particles that subsequently convert to photons in astrophysical magnetic fields. This model is consistent with all present observations of the 3.5 keV line, including galaxy clusters, spiral and dwarf galaxies and the galactic centre. Then, we discuss how a Cosmic-ALP-background can explain the excess of Soft X-rays in galaxy clusters.
Yuji Hasegawa, Atominsitut, TU-Wien
Weak-values of neutrons in double-slit experiment --- quantum Cheshire-Cat and weak-value as a complex number ---
Seminar room, Kenkyu honkan 3F Our group in Vienna is promoting neutron optical experiments, i.e., neutron interferometery and polarimetry: both experiments manifest the validity of quantum mechanical predictions with high precision. For instance, an experiment is carried out recently, which deals with error-disturbance uncertainty relation: we have experimentally tested error-disturbance uncertainty relations. Experimental results confirm the fact that the Heisenberg’s uncertainty relation is often violated and that the new relation derived by Ozawa is always larger than the limit. In addition, as an example of a counterfactual phenomenon of quantum mechanics, observation of so-called quantum Cheshire Cat is performed experimentally by using neutron interferometer. Experimental results suggest that pre- and post-selected neutrons travel through one of the arms of the interferometer while their magnetic moment is located in the other arm. In addition, we carried out an experiment to determine weak-value of 1/2-spin as a complex number: experimental results agree well with theoretical prediction. In my talk, I am going to give an overview of activities of weak-value/measurement. Then, I am going to explain neutron ineterferometric experiments concerning two aspects of weak-value/measurement.
Our group in Vienna is promoting neutron optical experiments, i.e., neutron interferometery and polarimetry: both experiments manifest the validity of quantum mechanical predictions with high precision. For instance, an experiment is carried out recently, which deals with error-disturbance uncertainty relation: we have experimentally tested error-disturbance uncertainty relations. Experimental results confirm the fact that the Heisenberg’s uncertainty relation is often violated and that the new relation derived by Ozawa is always larger than the limit. In addition, as an example of a counterfactual phenomenon of quantum mechanics, observation of so-called quantum Cheshire Cat is performed experimentally by using neutron interferometer. Experimental results suggest that pre- and post-selected neutrons travel through one of the arms of the interferometer while their magnetic moment is located in the other arm. In addition, we carried out an experiment to determine weak-value of 1/2-spin as a complex number: experimental results agree well with theoretical prediction. In my talk, I am going to give an overview of activities of weak-value/measurement. Then, I am going to explain neutron ineterferometric experiments concerning two aspects of weak-value/measurement.
References:
J. Erhart et al., Nature Phys. 8, 185 (2012).
T. Denkmayr et al., Nat. Comm. (2014) DOI: 10.1038/ncomms5492.
Eiichiro Kokubo, National Astronomical Observatory of Japan
Simulating Formation of Terrestrial Planets
Meeting room 3, Kenkyu honkan 1F
Recent exoplanet surveys revealed that terrestrial planets are ubiquitous in the Galaxy. In the standard scenario, a planetary system forms from a protoplanetary disk that consists of gas and dust. The standard scenario of terrestrial planet formation can be divided into three stages: (1) planetesimal formation, (2) protoplanet formation, and (3) planet formation. In stage (1), planetesimals form from dust. Planetesimals are small building blocks of solid planets. Planetesimals grow by mutual collisions to protoplanets or planetary embryos in stage (2). In stage (3) terrestrial planets are formed by giant impacts among protoplanets. Today these stages are investigated mainly by numerical simulations since they includes complex and non-linear processes. In the present talk, I review the basic elementary processes of terrestrial planet formation, showing some recent numerical simulations.
Hirotada Okawa, Waseda University
On the gravitational collapse in confined geometries
Meeting room 3, Kenkyu honkan 1F
t was recently pointed out that anti-de Sitter(AdS) spacetime is unstable against gravitational collapse. The pertubation in AdS does not simply decay away and can be reflected by AdS boundary to nonlinearly interact with one another. Confinement would play an important role in the nonlinear instability. For instance, how does the gravitational collapse occur by an effective confinement? In this presentation, I would like to show our results in an asymptotic flat spacetime and discuss open problems in this field after making a brief review.
Aravind Natarajan, University of Pittsburgh, IMPU
Probes of dark matter
Meeting room 1, Kenkyu honkan 1F
