Sneutrino Inflation with Asymmetric Dark Matter

The asymmetric dark matter scenario is known to give an interesting solution for the cosmic coincidence problem between baryon and dark matter densities. In the scenario, the dark matter asymmetry, which is translated to the dark matter density in the present universe, is transferred from the B-L asymmetry generated in the early universe. On the other hand, the generation of the B-L asymmetry is simply assumed, though many mechanisms for the generation are expected to be consistent with the scenario. We show that the generation of the asymmetry in the sneutrino inflation scenario works similarly to the asymmetric dark matter scenario, because the non-renormalizable operator which translates the B-L asymmetry to the dark matter asymmetry is naturally obtained by integrating right-handed neutrinos out. As a result, important issues concerning cosmology (inflation, the mass density of dark matter, and the baryon asymmetry of the universe) as well as neutrino masses and mixing have a unified origin, namely, the right-handed neutrinos.Comment: 11 pages, 4 figures; v2: reference added, Fig. 3 changed and explanation added; v3: version accepted for publication in PR

Universally Leptophilic Dark Matter From Non-Abelian Discrete Symmetry

The positron anomaly recently reported by the cosmic-ray measurements can be explained by the decaying dark matter scenario, where it decays mainly into leptons with the lifetime of O(10^26) second. When the dark matter is a fermionic particle, the lifetime of this order is known to be obtained by a dimension 6 operator suppressed by the unification scale 10^16 GeV, while such decay operators do not necessarily involve only leptons. In addition, the scenario would be spoiled if there exist lower-dimensional operators inducing the dark matter decay. We show in this letter that a single non-Abelian discrete symmetry such as A_4 is possible to prohibit all such harmful (non-leptonically coupled and lower-dimensional) operators. Moreover, the dark matter decays into charged leptons in a flavor-blind fashion due to the non-Abelian flavor symmetry, which results in perfect agreements not only with the PAMELA data but also with the latest Fermi-LAT data reported very recently. We also discuss some relevance between the discrete symmetry and neutrino physics.Comment: 13 pages, 2 tables, 1 figur

Lefschetz fibrations with small slope

We construct Lefschetz fibrations over $S^2$ which do not satisfy the slope inequality. This gives a negative answer to a question of Hain.Comment: 9 pages, 2 figures, Main changes are the corrections of the statement and proof of Theorem 1.5. This version correct the statements and proofs of Corollary 1.3 and 1.

Cryophilic fungi to denote fungi in cryosphere

第3回極域科学シンポジウム/第34回極域生物シンポジウム 11月27日（火） 国立極地研究所 ３階ラウン

Deformation and residual stress of T-shaped joints fabricated by laser-arc hybrid welding for steel bridge members

The version of record of this article, first published in Welding in the World, is available online at Publisher’s website: https://doi.org/10.1007/s40194-023-01650-zA series of experiments and analyses were performed for applying laser-arc hybrid welding to fabricating steel bridge components. Two-pass fully penetrated T-shaped joints using high-performance steel (SBHS400) having a 15-mm thickness were produced using hybrid welding. T-shaped joints having identical dimensions were manufactured using conventional arc welding. Without considering the inter-pass cooling time, the duration of hybrid welding was reduced by roughly 83% in comparison to that for GMAW. The average out-of-plane deformation caused by hybrid welding was decreased by 67% compared to arc welding. The fully coupled thermal elastic–plastic analyses were performed to replicate the distribution of residual stress in as-welded T-shaped joints. The analytical results indicated that the tensile residual stress range in hybrid-welded T-shaped joints was approximately one third (1/3) of that in arc-welded T-shaped joints. The weld joints produced by hybrid welding may have advantages over those produced by arc welding in terms of reducing welding deformation, decreasing welding residual stresses, and shortening welding time when manufacturing large steel bridge components

近代木造建築の壁構法と構造性能に関する研究 : 木摺漆喰壁の構成要素と水平力抵抗機構

学位の種別: 課程博士審査委員会委員 : （主査）東京大学准教授 藤田 香織, 東京大学教授 藤井 恵介, 東京大学教授 腰原 幹雄, 東京大学准教授 伊山 潤, 工学院大学教授 田村 雅紀, 職業能力開発総合大学校准教授 前川 秀幸University of Tokyo(東京大学

Taxonomic revision of the Typhula ishikariensis complex

publishedVersio

An Endoscopic Endonasal Approach for Early-Stage Olfactory Neuroblastoma: An Evaluation of 2 Cases with Minireview of Literature

We describe the clinical findings in two patients with pathologically diagnosed olfactory neuroblastoma (ONB) of the sinonasal area and the surgical methods used for its treatment. Using an endoscopic endonasal approach (EEA) without dura resection, along with radiotherapy, we successfully treated ONB at the Kadish stage A. One of our patients, however, experienced tumor recurrence 24 years after open surgery with radiotherapy that was conducted at another hospital. This patient was no longer eligible for radiotherapy, and the tumor was therefore resected with dura resection using an EEA combined with duraplasty. The dura resection with duraplasty using fascia lata and a pedicled nasal septal flap was minimally invasive. As with surgery without duraplasty, a postoperative computed tomography (CT) examination revealed that EEA with duraplasty led to quick improvement of the postoperative inflammatory response as well as pneumocranium. Here, we investigated whether to modify the method of surgery depending upon the primary site of early-stage ONB. We suggest that, in early-stage ONB, an endoscopic endonasal approach is an effective and less invasive method. It is also advisable to perform dura mater resection of the lesion site despite the absence of obvious intracranial invasions in image findings

Charpy absorbed energy in simulated heat-affected zone of laser-arc hybrid welded joints by high-strength steel for bridge structures

The application of laser-arc hybrid welding (so-called, hybrid welding) to the fabrication of steel bridge members has recently been investigated. One-pass full-penetration butt joints of steels for bridge high-performance structure (SBHS400 and SBHS500) with a thickness of 15 mm were performed by hybrid welding. The sound butt joints by hybrid welding were confirmed by a series of tests. The Charpy impact test was performed on the test pieces extracted from the hybrid welded butt joints with specified test temperatures. A phenomenon known as fracture path deviation (FPD) occurred in most test pieces, due to a large variation in material properties of the heat-affected zone (HAZ), resulting in the difficulty of estimating the toughness of HAZ in hybrid welded joints. Therefore, the Charpy impact test was conducted on the test pieces subjected to the welding thermal cycle tests of hybrid welding, which can exclude the heterogeneity of material properties and obtain the Charpy absorbed energy of the HAZ with high accuracy. The test results indicated that FPD was not observed in all thermal cycle simulated test pieces because the uniform metallographic structures in the vicinity of the notch were formed by the simulated thermal cycle tests, and all thermal cycle simulated test pieces satisfied 47 J at the specified test temperatures, a value that prevents brittle fracture for SBHS. Besides, for investigating the effect of the high Charpy absorbed energy guaranteed by SBHS on the toughness of hybrid welded joints, the Charpy absorbed energy of the thermal cycle simulated test pieces of SBHS and those of conventional steel (SM400B) were compared. The results showed that some of the thermal cycle simulated test pieces of SM400B failed to satisfy 27 J, suggesting that SBHS may ensure a Charpy absorbed energy of 47 J or more in the HAZ of hybrid welded joints.Chen G., Hirohata M., Sakai N., et al. Charpy absorbed energy in simulated heat-affected zone of laser-arc hybrid welded joints by high-strength steel for bridge structures. International Journal of Advanced Manufacturing Technology 127, 2655 (2023); https://doi.org/10.1007/s00170-023-11420-2