The Role of Psychological Factors in Judo: A Systematic Review

(1) Background: Psychological parameters are relevant in the practice of judo. Previous studies have shown that parameters such as anxiety or motivation can have a negative or positive impact on the athlete\u2019s performance and general well-being, depending on the athlete\u2019s perception. This systematic review aimed to summarize the studies examining the influence of various psychological parameters on well-being and performance in judo athletes; (2) Methods: We followed preferred reporting elements for systematic reviews and meta-analyses. We searched the Web of Science database for studies that explained the role of these parameters in elite athletes. Of the 286 articles initially identified, 17 met our eligibility criteria and were included in the review. In total, we analyzed data from 721 judo athletes; (3) Results: The studies found have demonstrated the impact of various psychological parameters during high-level performance and how these parameters can influence and lead an athlete to win or lose a competition. The feelings of tension, anger, anxiety, and nervousness were significantly increased in athletes who were facing defeat, while a decrease in the same segments and an increase in motivation among athletes who were experiencing better performance was observed. Further research under standardized conditions is needed to better understand the effects of these parameters on judo athletes; (4) Conclusions: Considering the athlete\u2019s psychological state can affect performance, and it is therefore important to monitor and train these factors

SU(2)-invariant reduction of the 3+1 dimensional Ashtekar's gravity

We consider a space-time with spatial sections isomorphic to the group manifold of SU(2). Triad and connection fluctuations are assumed to be SU(2)-invariant. Thus, they form a finite dimensional phase space. We perform non-perturbative path integral quantization of the model. Contarary to previous claims the path integral measure appeared to be non-singular near configurations admitting additional Killing vectors. In this model we are able to calculate the generating functional of Green functions of the reduced phase space variables exactly.Comment: 12 page

Non-crystallographic reduction of generalized Calogero-Moser models

We apply a recently introduced reduction procedure based on the embedding of non-crystallographic Coxeter groups into crystallographic ones to Calogero–Moser systems. For rational potentials the familiar generalized Calogero Hamiltonian is recovered. For the Hamiltonians of trigonometric, hyperbolic and elliptic types, we obtain novel integrable dynamical systems with a second potential term which is rescaled by the golden ratio. We explicitly show for the simplest of these non-crystallographic models, how the corresponding classical equations of motion can be derived from a Lie algebraic Lax pair based on the larger, crystallographic Coxeter group

Asymptotic behaviour of cylindrical waves interacting with spinning strings

We consider a family of cylindrical spacetimes endowed with angular momentum that are solutions to the vacuum Einstein equations outside the symmetry axis. This family was recently obtained by performing a complete gauge fixing adapted to cylindrical symmetry. In the present work, we find boundary conditions that ensure that the metric arising from this gauge fixing is well defined and that the resulting reduced system has a consistent Hamiltonian dynamics. These boundary conditions must be imposed both on the symmetry axis and in the region far from the axis at spacelike infinity. Employing such conditions, we determine the asymptotic behaviour of the metric close to and far from the axis. In each of these regions, the approximate metric describes a conical geometry with a time dislocation. In particular, around the symmetry axis the effect of the singularity consists in inducing a constant deficit angle and a timelike helical structure. Based on these results and on the fact that the degrees of freedom in our family of metrics coincide with those of cylindrical vacuum gravity, we argue that the analysed set of spacetimes represent cylindrical gravitational waves surrounding a spinning cosmic string. For any of these spacetimes, a prediction of our analysis is that the wave content increases the deficit angle at spatial infinity with respect to that detected around the axis.Comment: 25 pages, accepted for publication in Classical and Quantum Gravit

A Connection Approach to Numerical Relativity

We discuss a general formalism for numerically evolving initial data in general relativity in which the (complex) Ashtekar connection and the Newman-Penrose scalars are taken as the dynamical variables. In the generic case three gauge constraints and twelve reality conditions must be solved. The analysis is applied to a Petrov type \{1111\} planar spacetime where we find a spatially constant volume element to be an appropriate coordinate gauge choice.Comment: 17 pages, LaTe

PKS 2250−351: A Giant Radio Galaxy in Abell 3936

We present a detailed analysis of the radio galaxy PKS , a giant of 1.2 Mpc projected size, its host galaxy, and its environment. We use radio data from the Murchison Widefield Array, the upgraded Giant Metre-wavelength Radio Telescope, the Australian Square Kilometre Array Pathfinder, and the Australia Telescope Compact Array to model the jet power and age. Optical and IR data come from the Galaxy And Mass Assembly (GAMA) survey and provide information on the host galaxy and environment