Ryohei Kobayashi 교수

The authors construct a Lieb-Schultz-Mattis (LSM)-type theorem applicable for abelian gauge theories without matter. This theorem is based on generalized global symmetries acting on Wilson lines. It provides strong constraints on possible phases, realized in lattice gauge theories. The generalized LSM theorem is demonstrated on the example of a U(1) gauge theory that simulates the quantum dimer model on a bipartite lattice. The authors find a mixed `t Hooft anomaly involving the generalized glob

The reaction scheme of rotary catalysis and the torque generation mechanism of bovine mitochondrial F₁ (bMF₁) were studied in single-molecule experiments. Under ATP-saturated concentrations, high-speed imaging of a single 40-nm gold bead attached to the γ subunit of bMF₁ showed 2 types of intervening pauses during the rotation that were discriminated by short dwell and long dwell. Using ATPγS as a slowly hydrolyzing ATP derivative as well as using a functional mu

IF₁ is a natural inhibitor protein for mitochondrial F_oF₁ ATP synthase that blocks catalysis and rotation of the F₁ by deeply inserting its N-terminal helices into F₁. A unique feature of IF₁ is condition-dependent inhibition; although IF₁ inhibits ATP hydrolysis by F₁, IF₁ inhibition is relieved under ATP synthesis conditions. To elucidate this condition-dependent inhibition mechanism, we have per

Resta proposed a definition of the electric polarization in one-dimensional systems in terms of the ground-state expectation value of the large gauge transformation operator. Vanishing of the expectation value in the thermodynamic limit implies that the system is a conductor. We study Resta's polarization amplitude (expectation value) in the $S=1/2$ XXZ chain and its several generalizations, in the gapless conducting Tomonaga-Luttinger liquid phase. We obtain an analytical expression in the lowe

Selenium, one of the essential trace minerals, is present <i>in vivo</i> in form of selenoproteins. Iodothyronine deiodinase, a selenoprotein, is involved in the activation and inactivation of thyroid hormone. Therefore, patients with selenium deficiency may present changes in thyroid hormone levels due to inhibition of T4 to T3 conversion; however, this assumption is still under debate. In the present study, we retrospectively investigated the thyroid function in 22 patients with selenium defic

Given the algebraic data characterizing any (2+1)D bosonic or fermionic topological order with a global symmetry group $G = \mathrm{U}(1) \rtimes H$, we construct a (3+1)D topologically invariant path integral in the presence of a curved background $G$ gauge field, as an exact combinatorial state sum. Specifically, the $\mathrm{U}(1)$ component of the $G$ gauge field can have a non-trivial second Chern class, extending previous work that was restricted to flat $G$ bundles. Our construction expre

A bstract We examine topological terms of (2 + 1)d sigma models and their consequences in the light of classifications of invertible quantum field theories utilizing bordism groups. In particular, we study the possible topological terms for the U( N ) / U(1) N flag-manifold sigma model in detail. We argue that the Hopf-like term is absent, contrary to the expectation from a nontrivial homotopy group π 3 (U( N ) / U(1) N ) = ℤ, and thus skyrmions cannot become anyons with arbitrary statistics. In

We investigate symmetry-preserving gapped boundary of $(2+1)$-dimensional $[(2+1)\mathrm{D}]$ topological phases with global symmetry, which can be either bosonic or fermionic. We develop a general algebraic description for gapped boundary condition for symmetry-enriched or fermionic topological phases, extending the framework of Lagrangian algebra anyon for bosonic phases without symmetry. We then focus on application to the case with U(1) symmetry. We derive new obstructions to symmetry-preser

ATPase inhibitory factor 1 (IF1) is a mitochondrial regulatory protein that blocks ATP hydrolysis of F1-ATPase, by inserting its N-terminus into the rotor-stator interface of F1-ATPase. Although previous studies have proposed a two-step model for IF1-mediated inhibition, the underlying molecular mechanism remains unclear. Here, we analysed the kinetics of IF1-mediated inhibition under a wide range of [ATP]s and [IF1]s, using bovine mitochondrial IF1 and F1-ATPase. Typical hyperbolic curves of in

In order to synthesize the potent nuclear factor (NF)-κB inhibitor, (2S,3S,4S)-dehydroxymethylepoxyquinomycin (DHMEQ), in a large scale, a new route for its corresponding racemic precursor, dihexanoyl (2R*,3R*,4R*)-DHMEQ, was developed. By employing both hydroquinone and benzoquinone intermediates, the total yield, reproducibility, and synthetic steps were improved and the synthetic cost was reduced.

Okicamelliaside, a glucoside of ellagic acid with potent anti-degranulation activity, was synthesized from ellagic acid. The regioselectivity, solubility, and high reactivity of the intermediates throughout the synthesis were obtained by the complementary use of triisopropylsilyl (TIPS) and methoxyethoxymethyl (MEM) protective groups on the aglycone skeleton.

In this paper, we provide state sum path integral definitions of exotic invertible topological phases proposed in the recent paper by Hsin, Ji, and Jian [arXiv:2105.09454 [cond-mat.str-el]. The exotic phase has time-reversal $(T)$ symmetry, and depends on a choice of the space-time structure called the Wu structure. The exotic phase cannot be captured by the classification of any bosonic or fermionic topological phases and thus gives a novel class of invertible topological phases. When the $T$ s

We discuss a way to construct a commuting projector Hamiltonian model for a ($3+1$)-dimensional topological superconductor in class DIII. The wave function is given by a sort of string net of the Kitaev wire, decorated on the time-reversal ($T$) domain wall. Our Hamiltonian is provided on a generic three-dimensional (3D) manifold equipped with a discrete form of the spin structure. We will see how the 3D spin structure induces a 2D spin structure (called a ``Kasteleyn'' direction on a 2D lattice