Symmetric decreasing rearrangement is a mathematical concept used primarily in the field of analysis, particularly in the study of functions and measures. It is a technique that involves rearranging a sequence or a measurable function in such a way that the new arrangement is symmetric and non-increasing (i.e., it decreases or stays constant).
Articles by others on the same topic
The symmetric decreasing rearrangement of a measurable function is the radial, radially nonincreasing function whose superlevel sets are centered balls with the same measures as those of . It preserves norms, and the Pólya-Szegő inequality gives .