2008/12/06 by Boris Rubin, Rubin, Boris
Mathematics · #44A12 #52A38 #FOS: Mathematics #Functional Analysis (math.FA) #Mathematics and Applications #Morphological variations and asymmetry #Point processes and geometric inequalities #math.FA #msc:44A12 #msc:52A38
paper · pdf · doi:10.48550/arxiv.0812.1300
41 pages
openalex publication_date 2008/12/06 · arxiv created 2009/03/30 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
The classical Busemann-Petty problem (1956) asks, whether origin-symmetric convex bodies in \mathbb Rn with smaller hyperplane central sections necessarily have smaller volumes. It is known, that the answer is affirmative if n≤ 4 and negative if n>4. The same question can be asked when volumes of hyperplane sections are replaced by other comparison functions having geometric meaning. We give unified exposition of this circle of problems in real, complex, and quaternionic n-dimensional spaces. All cases are treated simultaneously. In particular, we show that the Busemann-Petty problem in the quaternionic n-dimensional space has an affirmative answer if and only if n =2. The method relies on the properties of cosine transforms on the unit sphere. Possible generalizations are discussed.