Abstract
The paper is devoted to weighted spaces ℒ w p (G) on a locally compact group G. If w is a positive measurable function on G, then the space ℒ w p (G), p ≥ 1, is defined by the relation ℒ w p (G) = {f: fw ∈ ℒ p (G)}. The weights w for which these spaces are algebras with respect to the ordinary convolution are treated. It is shown that, for p > 1, every sigma-compact group admits a weight defining such an algebra. The following criterion is proved (which was known earlier for special cases only): a space ℒ w p (G) is an algebra if and only if the function w is semimultiplicative. It is proved that the invariance of the space ℒ w p (G) with respect to translations is a sufficient condition for the existence of an approximate identity in the algebra ℒ w p (G). It is also shown that, for a nondiscrete group G and for p > 1, no approximate identity of an invariant weighted algebra can be bounded.
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Original Russian Text © Yu. N. Kuznetsova, 2008, published in Matematicheskie Zametki, 2008, Vol. 84, No. 4, pp. 567–576.
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Kuznetsova, Y.N. Invariant Weighted Algebras ℒ w p (G). Math Notes 84, 529–537 (2008). https://doi.org/10.1134/S0001434608090241
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DOI: https://doi.org/10.1134/S0001434608090241