We define a new hierarchy of isotopy invariants of colored oriented links through oriented tangle diagrams. We prove the colored braid relation and the Markov trace property explicitly.

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Music performance anxiety (MPA), or stage fright in music performance, is a serious problem for many musicians, because performance impairment accompanied by MPA can threaten their career. The present study sought to clarify on how a social-evaluative performance situation affects subjective, autonomic, and motor stress responses in pianists. Measurements of subjective state anxiety, heart rate (HR), sweat rate (SR), and electromyographic (EMG) activity of upper extremity muscles were obtained while 18 skilled pianists performed a solo piano piece(s) of their choice under stressful (competition) and non-stressful (rehearsal) conditions. Participants reported greater anxiety in the competition condition, which confirmed the effectiveness of stress manipulation. The HR and SR considerably increased from the rehearsal to competition condition reflecting the activation of sympathetic division of the autonomic nervous system. Furthermore, participants showed higher levels of the EMG magnitude of proximal muscles (biceps brachii and upper trapezius) and the co-contraction of antagonistic muscles in the forearm (extensor digitorum communis and flexor digitorum superficialis) in the competition condition. Although these responses can be interpreted as integral components of an adaptive biological system that creates a state of motor readiness in an unstable or unpredictable environment, they can adversely influence pianists by disrupting their fine motor control on stage and by increasing the risk of playing-related musculoskeletal disorders.

The proximal-to-distal segmental sequence has been identified in many sports activities, including baseball pitching and ball kicking. However, proximal-to-distal sequential muscle activity has not been identified. The aims of this study were to establish whether sequential muscle activity does occur and, if it does, to determine its functional role. We recorded surface electromyograms (EMGs) for 17 muscles from the upper extremity and abdomen during overarm throwing and detected the onset and peak times as indices of muscle activity. The following electromyographic properties were commonly identified in the participants. First, sequential muscle activity was observed from the scapular protractors to the shoulder horizontal flexors and from the shoulder horizontal flexors to the elbow extensor, but not from the elbow extensor to the wrist flexor or forearm pronator. Secondly, the external oblique contralateral to the throwing arm became activated before the ipsilateral external oblique. This sequence is considered to be very effective for the generation of high force and energy in the trunk. Thirdly, the ipsilateral external oblique began its activity almost at foot strike. Finally, the main activity of the rectus abdominis appeared just before the point of release.

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In view of its physical importance in predicting the order of chiral phase transitions in QCD and frustrated spin systems, we perform the conformal bootstrap program of O(n) × O(2)-symmetric conformal field theories in d = 3 dimensions with a special focus on n = 3 and 4. The existence of renormalization group fixed points with these symmetries has been controversial over years, but our conformal bootstrap program provides the non-perturbative evidence. In both n = 3 and 4 cases, we find singular behaviors in the bounds of scaling dimensions of operators in two different sectors, which we claim correspond to chiral and collinear fixed points, respectively. In contrast to the cases with larger values of n, we find no evidence for the anti-chiral fixed point. Our results indicate the possibility that the chiral phase transitions in QCD and frustrated spin systems are continuous with the critical exponents that we predict from the conformal bootstrap program.

Random electron systems show rich phases such as Anderson insulator, diffusive metal, quantum Hall and quantum anomalous Hall insulators, Weyl semimetal, as well as strong/weak topological insulators. Eigenfunctions of each matter phase have specific features, but owing to the random nature of systems, determining the matter phase from eigenfunctions is difficult. Here, we propose the deep learning algorithm to capture the features of eigenfunctions. Localization-delocalization transition, as well as disordered Chern insulator-Anderson insulator transition, is discussed.Introduction-More than half a century has passed since the discovery of Anderson localization, 1) and the random electron systems continue to attract theoretical as well as experimental interest. Symmetry classification of topological insulators 2-5) based on the universality classes of random noninteracting electron systems 6, 7) gives rise to a fundamental question:can we distinguish the random topological insulator from Anderson insulators? Note that topological numbers are usually defined in the randomness free systems via the integration of the Berry curvature of Bloch function over the Brillouin zone, although topological numbers in random systems have recently been proposed. [8][9][10] Determining the phase diagram and the critical exponents requires large-scale numerical simulation combined with detailed finite size scaling analyses. 11-14) This is because, owing to large fluctuations of wavefunction amplitudes, it is almost impossible to judge whether the eigenfunction obtained by diagonalizing small systems is localized or delocalized, or whether the eigenfunction is a chiral/helical edge state of a topological insulator. In fact, it often happens that eigenfunctions in the localized phase seem less localized than those in the delocalized phase [see Figs. 1(b) and 1(c) for example]. * ootsuki t@msi.co.jp † ohtsuki@sophia.ac.jp J. Phys. Soc. Jpn. LETTERSRecently, there has been great progress on image recognition algorithms 15) based on deep machine learning. 16,17) Machine learning has recently been applied to several problems of condensed matter physics such as Ising and spin ice models 18,19) and strongly correlated systems. [20][21][22][23][24][25] In this Letter, we test the image recognition algorithm to determine whether the eigenfunctions for relatively small systems are localized/delocalized, and topological/nontopological. As examples, we test two types of two-dimensional (2D) quantum phase c . We impose periodic boundary conditions in x-and y-directions, and diagonalize systems of 40 × 40. From the resulting 3200 eigenstates with Kramers degeneracy, we pick up the 1600th eigenstate (i.e., a state close to the band center). For simplicity, the maximum modulus of the eigenfunction is shifted to the center of the system. Changing W and the seed of the random number stream (Intel MKL MT2023), we prepare 2000 samples of states, i.e., 1000 for W < W SU2 c and 1000 for W > W SU2 c. We then teach the machine

Epimorphisms between 2-bridge link groups TOMOTADA OHTSUKI ROBERT RILEY MAKOTO SAKUMA We give a systematic construction of epimorphisms between 2-bridge link groups. Moreover, we show that 2-bridge links having such an epimorphism between their link groups are related by a map between the ambient spaces which only have a certain specific kind of singularity. We show applications of these epimorphisms to the character varieties for 2-bridge links and π 1 -dominating maps among 3-manifolds. 57M25; 57M05, 57M50Dedicated to the memory of Professor Heiner Zieschang