In this paper we give an operator theoretic version of a recent result of F. J. Martín-Reyes and A. de la Torre concerning the problem of finding necessary and sufficient conditions for a nonsingular point transformation to satisfy the Pointwise Ergodic Theorem in Lp. We consider a positive conservative contraction T on L1 of a σ-finite measure space (X, F, μ), a fixed function e in L1 with e > 0 on X, and two positive measurable functions V and W on X. We then characterize the pairs (V,W) such that for any f in Lp(V dμ) the averages
R0 n (f,e) = (Σn k=0 Tk f) / (Σn k=0 Tk e)
converge almost everywhere to a function in Lp(W dμ). The characterizations are given for all p, 1 ≤ p < ∞.
@article{urn:eudml:doc:41236, title = {Weighted Lp spaces and pointwise ergodic theorems.}, journal = {Publicacions Matem\`atiques}, volume = {39}, year = {1995}, pages = {273-283}, mrnumber = {MR1370886}, zbl = {0853.47004}, language = {en}, url = {http://dml.mathdoc.fr/item/urn:eudml:doc:41236} }
Sato, Ryotaro. Weighted Lp spaces and pointwise ergodic theorems.. Publicacions Matemàtiques, Tome 39 (1995) pp. 273-283. http://gdmltest.u-ga.fr/item/urn:eudml:doc:41236/