로저스 다이로그 함수 (Rogers dilogarithm)

\(x\in (0,1)\)에서 로저스 dilogarithm을 다음과 같이 정의
\(L(x)=\operatorname{Li}_2(x)+\frac{1}{2}\log x\log (1-x)=-\frac{1}{2}\int_{0}^{x}\frac{\log(1-y)}{y}+\frac{\log(1-y)}{1-y}dy\)
\((-\infty,0],[1,\+\infty)\)를 제외한 복소평면으로 해석적확장됨

\(L(0)=0\)

\(L(1)=\frac{\pi^2}{6}\)

\(L_{2}(-1)=-\frac{\pi^2}{12}\)\(L(-1)=-\frac{\pi^2}{12}\)

\(\mbox{Li}_{2}(\frac{1}{2})=\frac{\pi^2}{12}-\frac{1}{2}\log^2(2)\)

\(\mbox{Li}_{2}(\frac{3-\sqrt{5}}{2})=\frac{\pi^2}{15}-\log^2(\frac{1+\sqrt{5}}{2})\)

\(\mbox{Li}_{2}(\frac{-1+\sqrt{5}}{2})=\frac{\pi^2}{10}-\log^2(\frac{1+\sqrt{5}}{2})\)

\(\mbox{Li}_{2}(\frac{1-\sqrt{5}}{2})=-\frac{\pi^2}{15}+\frac{1}{2}\log^2(\frac{1+\sqrt{5}}{2})\)

\(\mbox{Li}_{2}(\frac{-1-\sqrt{5}}{2})=-\frac{\pi^2}{10}+\frac{1}{2}\log^2(\frac{1+\sqrt{5}}{2})\)

\(L(x)+L(1-x)=L(1)\)

\(L(x)+L(y)=L(xy)+L(\frac{x(1-y)}{1-xy})+L\Left( \frac{y(1-x)}{1-xy} )\right)\)

목차