Application of resurgence theory to quantum physics attracts a great deal of attention. Resurgence theory was originally developed in ODE to obtain solutions from formal power-series solutions by use of nontrivial relation between formal solutions. It has been recently revealed that a similar relation between perturbative and nonperturbative contributions also exists in quantum theory. We give a brief review on the recent progress in the topic.

The origin of irreversibility is one of the most fundamental questions in theoretical physics, ever since the seminal consideration of Boltzmann. In this decade, thermalization of isolated quantum systems has attracted renewed attentions, in light of modern experiments such as ultracold atoms. In this article, we review the recent progress in this field, and discuss our theoretical result: the second law of thermodynamics and the fluctuation theorem for many-body pure quantum states.

One of the biggest uncertainties in nuclear physics lies on the equation of state for supranuclear matter, and neutron stars offer excellent testbeds to probe dense matter physics. In this article, I explain rather unexpected universal relations among neutron star observables that do not depend strongly on the underlying equation of state. In particular, I explain the relations among the stellar moment of inertial (I), tidal deformability (or Love number) and quadrupole moment (Q), hence the I-Love-Q relations. Such relations are extremely useful for probing fundamental physics. For example, one can use such relations to probe strong-field gravity without being affected by uncertainties in nuclear physics. Similar universal relations also hold among stellar multipole moments that resemble the well-known no-hair properties for black holes. I end this article by explaining the possible origin of such universality and speculating its relation to the universality that appears in second-order phase transitions in condensed matter physics.

We present results of the static three-quark potential obtained by using lattice QCD Monte-Carlo simulations with the Polyakov loop correlation function. We investigate the potential of O(200) sets of the three-quark geometries including not only the cases that three quarks are put at the vertices of acute, right, and obtuse triangles, but also the extreme cases such that three quarks are put in line. We find several new interesting features of the three-quark potential, and discuss its possible functional form.

The electric dipole moment (EDM) is a low-energy observable that only gets finite when the CP symmetry is violated, and serves as an exclusively sensitive probe in detecting new physics. EDMs, being mostly searched for in composite systems, are generated at the elementary level and come up through several nontrivial processes which lie in wide hierarchies of energy scale. In the present article, we review the current status of EDM study and discuss problems still to be solved, mainly focusing on those of diamagnetic atoms which contain the elementary, hadronic, nuclear and atomic physics and relate the CP violation of candidates of physics beyond the standard model to the final observables.