Fluid Dynamics in Curvilinear Coordinates without Fictitious Forces

Multiinstantons in Curvilinear Coordinates

The 'tHooft's 5N-parametric multiinstanton solution is generalized to curvilinear coordinates. Expressions can be simplified by the gauge transformation that makes η-symbols constant in the vierbein formalism. This generates the compensating addition to the gauge potential of pseudoparticles. Typical examples (4-spherical, 2 + 2-and 3 + 1-cylindrical coordinates) are studied and explicit formul...

Instantons in curvilinear coordinates

The multi-instanton solutions by ’tHooft and Jackiw, Nohl & Rebbi are generalized to curvilinear coordinates. Expressions can be notably simplified by the appropriate gauge transformation. This generates the compensating addition to the gauge potential of pseudoparticles. Singularities of the compensating connection are irrelevant for physics but affect gauge dependent quantities. The third con...

Entropic Forces in Geophysical Fluid Dynamics

Theories and numerical models of atmospheres and oceans are based on classical mechanics with added parameterizations to represent subgrid variability. Reformulated in terms of derivatives of information entropy with respect to large scale configurations, we find systematic forces very different from those usually assumed. Two examples are given. We see that entropic forcing by ocean eddies sys...

The Perfectly Matched Layer in Curvilinear Coordinates

In 1994 B erenger showed how to construct a perfectly matched absorbing layer for the Maxwell system in rectilinear coordinates. This layer absorbs waves of any wavelength and any frequency without reeection and thus can be used to artiicially terminate the domain of scattering calculations. In this paper we show how to derive and implement the B erenger layer in curvilinear coordinates (in two...

Fluid Dynamics Without Fluids