Nobuchika Okada, University of Alabama
Running Non-Minimal Inflation with Stabilized Inflaton Potential
In the context of the Higgs model involving gauge and Yukawa interactions with
the spontaneous gauge symmetry breaking, we consider $\lambda \phi^4$ inflation
with non-minimal gravitational coupling, where the Higgs field is identified as inflaton.
Since the inflaton quartic coupling is very small, once quantum corrections through the
gauge and Yukawa interactions are taken into account, the inflaton effective potential
most likely becomes unstable. In order to avoid this problem, we need to impose stability
conditions on the effective inflaton potential, which lead to not only non-trivial relations
among the particle mass spectrum of the model, but also correlations between the
inflationary predictions and the mass spectrum. For concrete discussion, we investigate
the minimal B−L extension of the Standard Model with identification of the B−L Higgs
field as inflaton. The stability conditions for the inflaton effective potential fix the mass
ratio among the B−L gauge boson, the right-handed neutrinos and the inflaton. This
mass ratio also correlates with the inflationary predictions. In other words, if the B−L
gauge boson and the right-handed neutrinos are discovered in future, their observed
mass ratio provides constraints on the inflationary predictions.
Takahiro Nishinaka, Yukawa Inst.
On the superconformal Index of Argues-Douglas theories
Argyres-Douglas (AD) theories are 4d N=2 superconformal field theories without useful Lagrangian descriptions. Therefore their superconformal indices cannot be evaluated by supersymmetric localization. In this talk, I will discuss our conjectural expression for the superconformal index of AD theories given in terms of 2d q-deformed Yang-Mills theory. Our conjecture is based on the S^1 x S^3 version of the AGT relation, and is perfectly consistent with the Higgs branch chiral rings, 2d chiral algebras, RG-flows, and the 3d reduction of AD theories.
Makoto Takamoto, The University of Tokyo
Thermal Synchrotron Radiation By Double Tearing Mode Reconnection - Application to the Crab Gamma-Ray Flares
Recent observations have revealed the Crab shows strong gamma-ray flares through synchrotron radiation whose maximum energy is around 370MeV with time-scale around 8 hours. Surprisingly, the observed energy is beyond the maximum energy of synchrotron photons radiated by electrons accelerated in MHD magnetic field. Although there are already some theoretical models which considered magnetic reconnection with an incredibly large spatial scale in Crab pulsar wind nebula, the origin of the flares is still controversial. In this presentation, we propose a new theoretical explanation of the Crab gamma-ray flare. Instead of considering phenomena in pulsar wind nebulae, we consider the double tearing mode (DTM) magnetic reconnection in a pulsar wind region. We obtained the evolution of DTM using resistive relativistic magneto-hydrodynamic simulations, and computed synthetic synchrotron spectra in the explosive reconnection phase. We found the variability of the Crab nebula/pulsar system, seen as flares, can be naturally explained by the DTM explosive phase in the striped wind. Our results also indicate that, in order to explain the Crab gamma-ray flare by DTM in the wind region, the magnetization parameter \sigma should be around 10^5 and the wind Lorentz factor be around 300.
Christopher Kelly (RBRC Brookhaven National Laboratory)
Standard-model prediction for direct CP violation in K→ππ decay
We discuss our recent publication (arXiv:1505.07863 [hep-lat]) of the first lattice QCD calculation of the complex kaon decay amplitude A_0 with physical kinematics, using a single 32^3 x 64 domain wall ensemble with G-parity spatial boundary conditions. We obtain approximate agreement with the experimental value for Re(A_0), which serves as a test of our method. Our prediction of Im(A_0) can be used to compute the direct CP violating ratio Re(ε′/ε), which we find to be ~2 sigma lower than the experimental value. This result provides a new test of the Standard Model theory of CP violation, one which can be made more accurate with increasing computer capability.
Sujoy Modak, KEK
Black Hole Information Paradox: a Door to New Physics?
Black hole information paradox (BHIP) is an old but unsolved problem. There is an intense controversy regarding a satisfactory resolution of the problem, which, in our point of view may lead to new physics. We consider a novel approach to address this issue.
The idea is based on
adapting, to the situation at hand, the modified versions of quantum theory involving spontaneous stochastic dynamical collapse of quantum states, which have been considered in attempts to deal with shortcomings of the standard Copenhagen interpretation of quantum mechanics, in particular, the issue known as “the measurement problem”. The new basic hypothesis is that this modified (stochastic) quantum behavior is enhanced in the region of high curvature so that the information encoded in the initial quantum state of the matter fields is rapidly erased as the black hole singularity is approached. We show that in this manner the complete evaporation of the black hole via Hawking radiation can be understood as involving no paradox.
REFERENCES:
[1] S. K. Modak, L. Ortíz, I. Peña and D.
Sudarsky, Phys. Rev. D 91,
124009 (2015).
[2] S. K. Modak, L. Ortíz, I. Peña and D.
Sudarsky, Gen. Rel. Grav. 47,
120 (2015).
[1] S. K. Modak, L. Ortíz, I. Peña and D.
Sudarsky, Phys. Rev. D 91,
124009 (2015).
[2] S. K. Modak, L. Ortíz, I. Peña and D.
Sudarsky, Gen. Rel. Grav. 47,
120 (2015).
Masahiro Hotta, Tohoku University
Quantum Energy Teleportation: Strong Local Passivity vs. LOCC
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
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
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
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