Ordered exponential and its features in Yang-Mills effective action

In this paper,we discuss some non-trivial relations for ordered exponentials on smooth Riemannian manifolds.As an example of application,we study the dependence of the four-dimensional quantum Yang–Mills effective action on the special gauge transformation with respect to the background field.Also,we formulate some open questions about a structure of divergences for a special type of regularization in the presence of the background field formalism.

SPEEDUP Code for Calculation of Transition Amplitudes via the Effective Action Approach

We present Path Integral Monte Carlo C code for calculation of quantum mechanical transition amplitudes for 1Dmodels.The SPEEDUP C code is based on the use of higher-order short-time effective actions and implemented to themaximal order p=18 in the time of propagation(Monte Carlo time step),which substantially improves the convergence of discretized amplitudes to their exact continuum values.Symbolic derivation of higher-order effective actions is implemented in SPEEDUP Mathematica codes,using the recursive Schrodinger equation approach.In addition to the general 1D quantum theory,developed Mathematica codes are capable of calculating effective actions for specific models,for general 2D and 3D potentials,as well as for a general many-body theory in arbitrary number of spatial dimensions.

Neuroimmune actions in the brain and interactions with the effects of alcohol

The neuroimmune system of the brain:Early studies(1990’s)on the neurological consequences of human immunodeficiency virus-1(HIV-1)infection in the brain were instrumental in establishing that specific brain cell types can function as an innate immune system within the brain and in that role influence cognitive function(Kaul et al.,2005).

A Neo Explanation of the"Mass-Velocity Relation

A reinterpretation of the well-known formula of the 'mass-velocity relation' is exactlyderived from a new viewpoint with new concepts, such as the finiteness of the transmitting velocityof force (TVF), effective action, and the coupled effect of the TVF for two EM fields, etc. Then, atrue meaning hidden in the Lorentz factor is exploited : i.e., when a charged particle is moving at aspeed v under an EM field, the effective action exerted on it by the field varies inversely with thespeed ratio β= v / U, where U is the TVF, which probably is equal to the propagation velocity ofEM field. The actual reduction of the effective action gives a false impression of mass gain.Accordingly, it is a major mistake in orientation to ascribe the (genuine) electrodynamics of movingbodies to any observation, or to any motion of an observer, while disregarding the facts of mutualaction.

Analysis of grinding mechanics and improved grinding force model based on randomized grain geometric characteristics

Too high grinding force will lead to a large increase in specific grinding energy, resulting in high temperature in grinding zone, especially for the aerospace difficult cutting metal materials,seriously affecting the surface quality and accuracy. At present, the theoretical models of grinding force are mostly based on the assumption of uniform or simplified morphological characteristics of grains, which is inconsistent with the actual grains. Especially for non-engineering grinding wheel,most geometric characteristics of grains are ignored, resulting in the calculation accuracy that cannot guide practical production. Based on this, an improved grinding force model based on random grain geometric characteristics is proposed in this paper. Firstly, the surface topography model of CBN grinding wheel is established, and the effective grain determination mechanism in grinding zone is revealed. Based on the known grinding force model and mechanical behavior of interaction between grains and workpiece in different stages, the concept of grain effective action area is proposed. The variation mechanism of effective action area under the influence of grain geometric and spatial characteristics is deeply analyzed, and the calculation method under random combination of five influencing parameters is obtained. The numerical simulation is carried out to reveal the dynamic variation process of grinding force in grinding zone. In order to verify the theoretical model, the experiments of dry grinding Ti-6Al-4 V are designed. The experimental results show that under different machining parameters, the results of numerical calculation and experimental measurement are in good agreement, and the minimum error value is only 2.1 %, which indicates that the calculation accuracy of grinding force model meets the requirements and is feasible. This study will provide a theoretical basis for optimizing the wheel structure, effectively controlling the grinding force range, adjusting the grinding zone temperature and improving the workpiece machining quality in the industrial grinding process.

QCD equation of state for heavy ion collisions

In this work, we calculate the equation of state（EoS） of quark gluon-plasma（QGP） using the CornwallJackiw-Tomboulis（CJT） effective action. We get the quark propagator by using the rank-1 separable model within the framework of the Dyson-Schwinger equations（DSEs）. The results from CJT effective action are compared with lattice QCD data. We find that, when μ is small, our results generally fit the lattice QCD data when T〉T_c,but show deviations at and below T_c. It can be concluded that the EoS of CJT is reliable when T〉T_c. Then,by adopting the hydrodynamic code UVH2＋1, we compare the CJT results of the multiplicity and elliptic flow v2 with the PHENIX data and the results from the original EoS in UVH2＋1. While the CJT results of multiplicities generally match the original UVH2＋1 results and fit the experimental data, the CJT results of v2 are slightly larger than the original UVH2＋1 results for centralities smaller than 40% and smaller than the original UVH2＋1 results for higher centralities.