2019/02/17 by Aleksandrov, Aleksei, Peller, Vladimir
#47A55 #47A60 47A55 #Classical Analysis and ODEs (math.CA) #Complex Variables (math.CV) #FOS: Mathematics #Functional Analysis (math.FA) #Spectral Theory (math.SP)
paper · doi:10.48550/arxiv.1902.06346
In this article we prove that for p>2, there exist pairs of self-adjoint operators (A1,B1) and (A2,B2) and a function f on the real line in the homogeneous Besov class B∞,11(\Bbb R2) such that the differences A2-A1 and B2-B1 belong to the Schatten--von Neumann class \boldsymbolSp but f(A2,B2)-f(A1,B1)\not∈\boldsymbolSp. A similar result holds for functions of contractions. We also obtain an analog of this result in the case of triples of self-adjoint operators for any p≥1