Macroscopic motion of classical spinning particles

1962 ◽  
Vol 26 (4) ◽  
pp. 821-830 ◽  
Author(s):  
P. Kyborg
Keyword(s):  
Spinning Particles ◽  
Macroscopic Motion

2000 Macromolecular Science and Engineering Award LectureThe versatility of azobenzene polymers

2001 ◽  
Vol 79 (7) ◽  
pp. 1093-1100 ◽  
Author(s):  
Almeria Natansohn ◽  
Paul Rochon
Keyword(s):  
Liquid Crystalline ◽  
Surface Deformation ◽  
Polymer Structure ◽  
Light Polarization ◽  
Polymer Materials ◽  
Science And Engineering ◽  
Crystalline Polymers ◽  
The Third ◽  
Macroscopic Motion ◽  
Azobenzene Groups

The well-known trans–cis–trans photoisomerization of azobenzenes produces at least three different kinds of motion in the polymer materials to which the azobenzenes are bound. The first is a photoinduced motion of the azobenzene groups only, and they can align in a selected position with respect to the light polarization. The second is a macroscopic motion of huge amounts of polymeric material, producing surface deformation, and the third is a reorganization of smectic domains in liquid crystalline polymers. These motions and their consequences are briefly discussed in relation to the polymer structure and some possible photonic applications are mentioned.Key words: photoinduced orientation, azobenzene polymers, surface gratings, photonics, thermochromism, photochromism, photorefractivity, photoinduced chirality and switching.

Internal Structure of Spinning Particles

1955 ◽  
Vol 100 (3) ◽  
pp. 924-931 ◽  
Author(s):  
David Finkelstein
Keyword(s):  
Internal Structure ◽  
Spinning Particles

scholarly journals SPINNING PARTICLES ON SPACELIKE HYPERSURFACES AND THEIR REST FRAME DESCRIPTION

1999 ◽  
Vol 14 (09) ◽  
pp. 1429-1484 ◽  
Author(s):  
FRANCESCO BIGAZZI ◽  
LUCA LUSANNA
Keyword(s):  
Spin Structure ◽  
Rest Frame ◽  
Negative Energy ◽  
Nonrelativistic Limit ◽  
Critical Discussion ◽  
Positive Energy ◽  
Spinning Particle ◽  
Spinning Particles ◽  
Spacelike Hypersurfaces ◽  
Energy Formula

A new spinning particle with a definite sign of the energy is defined on spacelike hypersurfaces after a critical discussion of the standard spinning particles. It is the pseudoclassical basis of the positive energy [Formula: see text] [or negative energy [Formula: see text]] part of the [Formula: see text] solutions of the Dirac equation. The study of the isolated system of N such spinning charged particles plus the electromagnetic field leads to their description in the rest frame Wigner-covariant instant form of dynamics on the Wigner hyperplanes orthogonal to the total four-momentum of the isolated system (when it is timelike). We find that on such hyperplanes these spinning particles have a nonminimal coupling only of the type "spin–magnetic field," like the nonrelativistic Pauli particles to which they tend in the nonrelativistic limit. The Lienard–Wiechert potentials associated with these charged spinning particles are found. Then, a comment is made on how to quantize the spinning particles respecting their fibered structure describing the spin structure.

scholarly journals Brittle Fracture Theory Describes the Onset of Frictional Motion

2019 ◽  
Vol 10 (1) ◽  
pp. 253-273 ◽  
Author(s):  
Ilya Svetlizky ◽  
Elsa Bayart ◽  
Jay Fineberg
Keyword(s):  
Friction Coefficient ◽  
Brittle Fracture ◽  
Static Friction ◽  
Quantitative Agreement ◽  
Interface Fracture ◽  
Earthquake Dynamics ◽  
Rupture Dynamics ◽  
Static Friction Coefficient ◽  
Fracture Theory ◽  
Macroscopic Motion

Contacting bodies subjected to sufficiently large applied shear will undergo frictional sliding. The onset of this motion is mediated by dynamically propagating fronts, akin to earthquakes, that rupture the discrete contacts that form the interface separating the bodies. Macroscopic motion commences only after these ruptures have traversed the entire interface. Comparison of measured rupture dynamics with the detailed predictions of fracture mechanics reveals that the propagation dynamics, dissipative properties, radiation, and arrest of these “laboratory earthquakes” are in excellent quantitative agreement with the predictions of the theory of brittle fracture. Thus, interface fracture replaces the idea of a characteristic static friction coefficient as a description of the onset of friction. This fracture-based description of friction additionally provides a fundamental description of earthquake dynamics and arrest.

BOUNDARY CONDITIONS IN FIRST QUANTIZATION

1991 ◽  
Vol 06 (22) ◽  
pp. 3997-4008 ◽  
Author(s):  
W. SIEGEL
Keyword(s):  
Field Theory ◽  
General Solution ◽  
Boundary Conditions ◽  
String Field Theory ◽  
Light Cone ◽  
Bosonic String ◽  
Second Quantization ◽  
Spinning Particles

In the BRST approach to first quantization, bosonic ghosts can cause ambiguities in the cohomology (and thus in second quantization). We show how nonminimal terms give a general solution to this problem, avoiding the need for “picture-changing operators.” As examples, we consider spinning particles, superparticles, covariantized light cone bosonic string field theory, and NSR superstring field theory.

scholarly journals UV constraints on massive spinning particles: lessons from the gravitino

2020 ◽  
Vol 2020 (2) ◽  
Author(s):  
Scott Melville ◽  
Diederik Roest ◽  
David Stefanyszyn
Keyword(s):  
Spinning Particles

scholarly journals Upper-Bound General Circulation of the Ocean: a Theoretical Exposition

2021 ◽  
Author(s):  
Hsien-Wang Ou
Keyword(s):  
Ocean Circulation ◽  
Upper Bound ◽  
First Principles ◽  
General Circulation ◽  
Large Scale ◽  
Companion Paper ◽  
Jet Stream ◽  
Equatorial Undercurrent ◽  
Macroscopic Motion ◽  
Dynamical Principle

This paper considers the general ocean circulation within the thermodynamical closure of our climate theory, which aims to deduce the generic climate state from first principles. The preceding papers of the theory have reduced planetary fluids to warm/cold masses and determined their bulk thermal properties, which provide prior constraints for the derivation of the upper-bound circulation when the potential vorticity is homogenized in moving masses. In a companion paper on the atmosphere, this upper bound is seen to reproduce the prevailing wind, forsaking therefore previous discordant explanations of the easterly trade and the polar jet stream. In this paper on the ocean, we again show that this upper bound may replicate broad features of the observed circulation, including a western-intensified subtropical gyre and a counter-rotating tropical gyre feeding the equatorial undercurrent. Together, we posit that PV homogenization may provide a unifying dynamical principle of the large-scale planetary circulation, which may be interpreted as the maximum macroscopic motion extractable by microscopic stirring --- within the confine of the thermal differentiation.

scholarly journals Complete set of quasi-conserved quantities for spinning particles around Kerr

2022 ◽  
Vol 12 (1) ◽  
Author(s):  
Geoffrey Compère ◽  
Adrien Druart
Keyword(s):  
Linear Order ◽  
Conserved Quantities ◽  
Killing Tensor ◽  
Kerr Geometry ◽  
Spinning Particles ◽  
Kerr Spacetime ◽  
Killing Tensors ◽  
Mixed Symmetry ◽  
Constants Of Motion ◽  
Complete Set

We revisit the conserved quantities of the Mathisson-Papapetrou-Tulczyjew equations describing the motion of spinning particles on a fixed background. Assuming Ricci-flatness and the existence of a Killing-Yano tensor, we demonstrate that besides the two non-trivial quasi-conserved quantities, i.e. conserved at linear order in the spin, found by Rüdiger, non-trivial quasi-conserved quantities are in one-to-one correspondence with non-trivial mixed-symmetry Killing tensors. We prove that no such stationary and axisymmetric mixed-symmetry Killing tensor exists on the Kerr geometry. We discuss the implications for the motion of spinning particles on Kerr spacetime where the quasi-constants of motion are shown not to be in complete involution.

Sign in / Sign up

Export Citation Format

Share Document