scholarly journals A formula for membrane mediated point particle interactions on near spherical biomembranes

2021 ◽  
Author(s):  
Charles M. Elliott ◽  
Philip J. Herbert
Keyword(s):  
Point Particle ◽  
Particle Interactions

scholarly journals QUANTUM GRAVITY CORRECTIONS TO PARTICLE INTERACTIONS

2002 ◽  
Vol 17 (15n17) ◽  
pp. 943-954 ◽  
Author(s):  
LUIS URRUTIA
Keyword(s):  
Quantum Gravity ◽  
Loop Quantum Gravity ◽  
Point Particle ◽  
Granular Structure ◽  
Power Counting ◽  
Length Scale ◽  
Particle Interactions ◽  
Planck Length ◽  
Dirac Equations ◽  
Effective Theories

An heuristic semiclassical procedure that incorporates quantum gravity induced corrections in the description of photons and spin 1/2 fermions is reviewed. Such modifications are calculated in the framework of loop quantum gravity and they arise from the granular structure of space at short distances. The resulting effective theories are described by power counting non-renormalizable actions which exhibit Lorentz violations at Planck length scale. The modified Maxwell an Dirac equations lead to corrections of the energy momentum relations for the corresponding particle at such scale. An action for the relativistic point particle exhibiting such modified dispersion relations is constructed and the first steps towards the study of a consistent coupling between these effective theories are presented.

Microstructure in the Sedimentation of Anisotropic and Deformable Particles

2005 ◽  
Author(s):  
David Saintillan ◽  
Eric Darve ◽  
Eric S. G. Shaqfeh
Keyword(s):  
Large Scale ◽  
Point Particle ◽  
Particle Interactions ◽  
Slip Boundary Conditions ◽  
Slip Boundary ◽  
Deformable Particles ◽  
Orientation Distributions ◽  
Viscous Droplets ◽  
Large Scale Simulations ◽  
Good Agreement

We use large-scale simulations to study the microstructure and concentration fluctuations in sedimenting suspensions of anisotropic particles such as spheroids, and deformable particles such as viscous droplets in the Stokes flow regime. An efficient method based on point-particle interactions is used allowing the simulation of full-scale suspensions with both periodic and slip boundary conditions, where the latter are used to qualitatively reproduce the effects of container walls. The concentration instability occurring in such systems is adequately captured, and we show that the formation of inhomogeneities is closely linked to the large-scale fluctuations of the disturbance flow. In particular, our simulations suggest that the presence of walls is important for a wavenumber selection to be observed, as they lead to a decay of the initial large-scale recirculation that otherwise dominates the flow in periodic systems. Results for the sedimentation rates and orientation distributions are also presented, and show good agreement with published experimental results.

Best Matching: Technical Details

2018 ◽  
Author(s):  
Flavio Mercati
Keyword(s):  
Point Particle ◽  
Euclidean Group ◽  
Scale Invariant ◽  
Similarity Group ◽  
N Body Problem ◽  
Technical Details ◽  
Matching Procedure ◽  
Principal Fibre ◽  
Principal Fibre Bundle ◽  
Gauge Connection

The best matching procedure described in Chapter 4 is equivalent to the introduction of a principal fibre bundle in configuration space. Essentially one introduces a one-dimensional gauge connection on the time axis, which is a representation of the Euclidean group of rotations and translations (or, possibly, the similarity group which includes dilatations). To accommodate temporal relationalism, the variational principle needs to be invariant under reparametrizations. The simplest way to realize this in point–particle mechanics is to use Jacobi’s reformulation of Mapertuis’ principle. The chapter concludes with the relational reformulation of the Newtonian N-body problem (and its scale-invariant variant).

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