{ "id": "1010.5336", "version": "v1", "published": "2010-10-26T08:48:36.000Z", "updated": "2010-10-26T08:48:36.000Z", "title": "Necessary Conditions for Fredholmness of Singular Integral Operators with Shifts and Slowly Oscillating Data", "authors": [ "Alexei Yu. Karlovich", "Yuri I. Karlovich", "Amarino B. Lebre" ], "comment": "26 pages", "categories": [ "math.FA" ], "abstract": "Suppose $\\alpha$ is an orientation-preserving diffeomorphism (shift) of $\\mR_+=(0,\\infty)$ onto itself with the only fixed points $0$ and $\\infty$. In \\cite{KKLsufficiency} we found sufficient conditions for the Fredholmness of the singular integral operator with shift \\[ (aI-bW_\\alpha)P_++(cI-dW_\\alpha)P_- \\] acting on $L^p(\\mR_+)$ with $1