# Some Write-Ups

These are some rather old write-ups of things which were once of interest to me...

This short document provides an overview of the current state of affairs concerning the forces excerpted by electromagnetic fields on spherical particles. 3 different methods are described (Radiative momentum balance, Maxwell-Stress-Tensor and the Dipole-Approximation + force density) and the Abraham-Minkowski controversy as well as the dispute between A. Rohrbach and P. C. Chaumet are reviewed.
Adobe Acrobat Dokument 3.3 MB
Bernoulli Numbers, Riemann Zeta-function & Trigonometric Series Representations
Notes on the famous Bernoulli numbers... They appear in the series representations of several trigonometric functions. Also, a relation to the Riemann Zeta function for even integers is derived.
Bernoulli.pdf
Adobe Acrobat Dokument 305.8 KB
Curvilinear coordinates
Extensive notes and derived expressions for curvilinear coordinates
LaplaceFinal.pdf
Adobe Acrobat Dokument 227.5 KB
Sommerfeld Expansion
Details and calculations concerning the Sommefeld expansion encountered in solid state physics
SommerfeldExpansion.pdf
Adobe Acrobat Dokument 249.6 KB
Stirling's Approximation
Some notes on Stirlings' Approximation of n!
SterlingsApproximation.pdf
Adobe Acrobat Dokument 251.2 KB
Moments of <r^n>(l,n) in quantum and classical mechanics.
This note derives a semi-classical expression for the expectation values of the moments of the radial coordinate, <r^n>, as a function of the angular momentum and principle quantum numbers l and n. The derivation starts with the time-average of the moment in Kepler orbits. A comparison to exact literature expressions is made.
Moments of r in QM and CM.pdf
Adobe Acrobat Dokument 437.0 KB