Masahiro Hotta, Tohoku University
Quantum Energy Teleportation: Strong Local Passivity vs. LOCC
Seminar room, Kenkyu honkan 3F
Quantum Energy teleportation (QET) is a protocol that allows one to teleport energy making use of pre-existing entanglement of the ground state of quantum many-body systems or quantum fields. I will review the latest results on QET and I will explain its implications on information thermodynamics, such as quantum Maxwell demons and Black Hole thermodynamics. I will also comment on current experimental prospects for QET via the quantum Hall effect.
Tomohiro Nakama, The University of Tokyo
Primordial black holes as a novel probe of primordial gravitational waves
Meeting Room 1, Kenkyu Honkan 1F
We propose a novel method to probe primordial gravitational waves by means of primordial black holes (PBHs). When the amplitude of primordial tensor perturbations on comoving scales much smaller than those relevant to Cosmic Microwave Background is very large, it induces scalar perturbations due to second-order effects substantially. If the amplitude of resultant scalar perturbations becomes too large, then PBHs are overproduced to a level that is inconsistent with a variety of existing observations constraining their abundance. This leads to upper bounds on the amplitude of initial tensor perturbations on super-horizon scales. The resultant PBH upper bounds turn out be tighter than other bounds obtained from Big Bang Nucleosynthesis and Cosmic Microwave Background.
Seishi Enomoto, University of Warsaw
Influence of interaction terms on non-perturbative particle production
Meeting Room 1, Kenkyu Honkan 1F
We have investigated effects of interaction terms on non-perturbative particle production. It is well known that a time-varying background induces abundant particle production, such as the preheating theory. As our conclusion, it is possible to induce particle production even if particles do not couple to the background directly. Such particles are produced through the interactions with other fields, which couple to a time-varying background. Especially, the resonant proccess due to the coherent oscillation of the background induces sizable amount of particles which do not couple to the background directly. In this talk, we will explain with a simple but illustrative model and show analytic and numerical results.
Koji Ishiwata, Kanazawa University
Grand Unification and Subcritical Hybrid Inflation
Meeting room 1, Kenkyu honkan 1F
We consider hybrid inflation for small couplings of the inflaton to matter such that the critical value of the inflaton field exceeds the Planck mass. It has recently been shown that inflation then continues at subcritical inflaton field values where quantum fluctuations generate an effective inflaton mass. The effective inflaton potential interpolates between a quadratic potential at small field values and a plateau at large field values. An analysis of the allowed parameter space leads to predictions for the scalar spectral index n_s and the tensor-to-scalar ratio r similar to those of natural inflation. Using the ranges for n_s and r favored by the Planck data, we find that the energy scale of the plateau is constrained to the interval (1.6 − 2.4) × 10^16 GeV, which includes the energy scale of gauge coupling unification in the supersymmetric standard model. The tensor-to-scalar ratio is predicted to satisfy the lower bound r > 0.049 for 60 e-folds before the end of inflation.
Lev Vaidman, Tel Aviv University
Counterfactual Communication
Seminar Room, Kenkyu Honkan 3F
Counterfactual communication is a communication without particles in the transmission channel. Since there are no particles to observe, it apparently cryptographically secure because Eve has nothing to eavesdrop on. However, the issue is highly controversial. I will describe: interaction-free measurements, counterfactual key distribution, and direct counterfactual communication protocols. Analyzing the weak trace left in the transmission channel, I will argue that counterfactual communication is possible only for one bit value.
Lev Vaidman, Tel Aviv University
Asking Photons Where They Have Been
Seminar room, Kenkyu honkan 3F
Experimental evidence obtained from photons passing through a nested Mach-Zehnder interferometer shows that they have been in the parts of the interferometer through which they could not have possibly pass. The meaning of these results and numerous objections are discussed. It is argued that the most simple and clear explanation is given in the framework of the two-state vector formalism of quantum theory.
Junichiro Kawamura, Waseda Univ.
LHC phenomenology of natural MSSM with non-universal gaugino masses at the unification scale
Meeting Room 322, Kenkyu Honkan 3F
We study collider phenomenology in the supersymmetric Standard Model with a certain type of non-universal gaugino masses at the gauge coupling unification scale, motivated by the little hierarchy problem. In this scenario, especially the wino mass is relatively large compared to the gluino mass at the unification scale, and the heavy wino can relax the fine-tuning of the higgsino mass parameter,so-called μ parameter. Besides, it will enhance the lightest Higgs boson mass due to the relatively large left-right mixing of top squarks through the renormalization group (RG) effect. Then 125GeV Higgs boson could be accomplished, even if the top squarks are lighter than 1TeV and the μ parameter is within a few hundreds GeV. The right-handed top squark tends to be lighter than the other sfermions due to the RG runnings, then we focus on the top squark search at the LHC. Since the top squark is almost right-handed and the higgsinos are nearly degenerate, 2b + MET channel is the most sensitive to this scenario. We figure out current and expected experimental bounds on the lightest top squark mass and model parameters at the gauge coupling unification scale.
Yoshinori Matsuo, University of Crete
Hyperscaling-violating Lifshitz hydrodynamics from black-holes
Meeting Room 322, Kenkyu Honkan 3F
Non-equilibrium black hole horizons are considered in scaling theories with generic Lifshitz invariance and an unbroken U(1) symmetry. There is also a special form of hyperscaling violation associated with a non-trivial conduction exponent. The boundary stress tensor is computed and renormalized, and the associated hydrodynamic equations are derived. Upon a non-trivial redefinition of boundary sources associated with the U(1) gauge field, the equations are mapped to the standard non-relativistic hydrodynamics equations coupled to a mass current and an external Newton potentials. The shear viscosity to entropy ratio is the same as in the relativistic case.
Rainer Sommer, DESY
The strong coupling from lattice QCD
Room 244, 4 go-kan 2F
After an introduction into what the strong coupling is, and how QCD discretized on a space-time lattice works, I discuss which methods are available to use lattice QCD in order to extract the strong coupling from experimental information. I then briefly review the status of these computations including the world average of the FLAG2 review and more recent developments.
Satoshi Ohya, Institute Quantum Science, Nihon University
BPS Monopole in the Space of Boundary Conditions
Seminar room, Kenkyu honkan 3F
