A note on the Gauss decomposition of the elliptic Cauchy matrix
Explicit formulas for the Gauss decomposition of elliptic Cauchy type matrices are derived in a very simple way. The elliptic Cauchy identity is an immediate corollary.
arXiv subjects
Publications and source records attributed to S. Ruijsenaars.
Explicit formulas for the Gauss decomposition of elliptic Cauchy type matrices are derived in a very simple way. The elliptic Cauchy identity is an immediate corollary.
We reconsider the Euclidean version of the photon number integral introduced in ref 1. This integral is well defined for any smooth non-self-intersecting curve in $\R^N$. Besides studying general features of this integral (including it s conformal invariance), we evaluate it explicitly for the ellipse. The result is $n_{ellipse}=(ξ^{-1}+ξ)π^2$, where $ξ$ is the ratio of the minor and major axes. This is in agreement with the previous result $n_{circle}=2π^2$ and also with the conjecture that the minimum value of $n$ for any plane curve occurs for the circle.