230 research outputs found
Nonvanishing Finite Scalar Mass in Flux Compactification
We study possibilities to realize a nonvanishing finite Wilson line (WL)
scalar mass in flux compactification. Generalizing loop integrals in the
quantum correction to WL mass at one-loop, we derive the conditions for the
loop integrals and mode sums in one-loop corrections to WL scalar mass to be
finite. We further guess and classify the four-point and three-point
interaction terms satisfying these conditions. As an illustration, the
nonvanishing finite WL scalar mass is explicitly shown in a six dimensional
scalar QED by diagrammatic computation and effective potential analysis. This
is the first example of finite WL scalar mass in flux compactification.Comment: 20 pages, 1 figur
A cyclic analogue of multiple zeta values
We consider a cyclic analogue of multiple zeta values (CMZVs), which has two
kinds of expressions; series and integral expression. We prove an
`integralseries' type identity for CMZVs. By using this identity, we
construct two classes of -linear relations among CMZVs. One of them
is a generalization of the cyclic sum formula for multiple zeta-star values. We
also give an alternative proof of the derivation relation for multiple zeta
values
Lagrangian mapping class groups from a group homological point of view
We focus on two kinds of infinite index subgroups of the mapping class group
of a surface associated with a Lagrangian submodule of the first homology of a
surface. These subgroups, called Lagrangian mapping class groups, are known to
play important roles in the interaction between the mapping class group and
finite-type invariants of 3-manifolds. In this paper, we discuss these groups
from a group (co)homological point of view. The results include the
determination of their abelianizations, lower bounds of the second homology and
remarks on the (co)homology of higher degrees. As a by-product of this
investigation, we determine the second homology of the mapping class group of a
surface of genus 3.Comment: 20 pages. The proof of Lemma 4.2 is corrected. To appear in Algebraic
& Geometric Topolog
Changes in Knowledge Levels through Lectures on Radiotherapy to Nursing Students in Japan
Background:Recently, the number of patients choosing radiotherapy is increasing in Japan. It is necessary for even nurses to have knowledge of radiotherapy. We measured the degree of awareness with a lecture on how a nursing student can obtain knowledge of radiotherapy.Materials and methods: Forty nursing students who were in their third year and preparing for their national nursing certification in two months were recruited. The 90-min lecture covered a range of topics from general theories to specific concepts. The students were not informed that they would be required to fill a survey at the end of the lecture. This was to avoid bias that could occur from knowing in advance that a survey would be conducted.Results: The following items below were particularly remarkable. The distinction between the radiologist and the radiation oncologist. The radiotherapy is a local therapy. The pain from bone metastasis could be relieved.Conclusion: Students had very little knowledge on radiotherapy before the lecture. the results of this study indicated the need to increase the number of lectures on radiotherapy for nursing as well medical students. As the number of radiotherapy patients increases
Wide-bandgap GaN-based watt-class photonic-crystal lasers
青色GaN系フォトニック結晶レーザーの高出力・高ビーム品質動作に成功 --次世代の高品位レーザー加工、高輝度照明、水中LiDAR等の実現に向けて--. 京都大学プレスリリース. 2022-11-04.Short-wavelength (blue-violet-to-green) lasers with high power and high beam quality are required for various applications including the machining of difficult-to-process materials and high-brightness illuminations and displays. Promising light sources for such applications are wide-bandgap GaN-based photonic-crystal surface-emitting lasers (PCSELs), which are based on two-dimensional resonance in the photonic crystal. Developments of these devices have lagged behind those of longer-wavelength GaAs-based PCSELs, because device designs for achieving robust two-dimensional resonance and a nanofabrication process that avoids introducing disorders have remained elusive for wide-bandgap GaN-based materials. Here, we address these issues and successfully realize GaN-based PCSELs with high, watt-class (>1 W) output power and a circular, single-lobed beam with a very narrow (~0.2°) divergence angle at blue wavelengths. In addition, we demonstrate continuous-wave operation with a high output power (~320 mW) and a high beam quality (M²~1). Our results will enable the use of GaN-based PCSELs in the above-mentioned applications
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