In this paper, we introduce the L p geominimal surface area for all −n = p < 1, which extends the classical geominimal surface area (p = 1) by Petty and the L p geominimal surface area by Lutwak (p > 1). Our extension of the L p geominimal surface area is motivated by recent work on the extension of the L p affine surface area -a fundamental object in (affine) convex geometry. We prove some properties for the L p geominimal surface area and its related inequalities, such as, the affine isoperimetric inequality and a Santaló style inequality. Cyclic inequalities are established to obtain the monotonicity of the L p geominimal surface areas. Comparison between the L p geominimal surface area and the p-surface area is also provided.2010 Mathematics Subject Classification: 52A20, 53A15
Introduction and Overview of ResultsThe classical isoperimetric problem asks: what is the minimal area among all convex bodies (i.e., convex compact subsets with nonempty interior) K ⊂ R n with volume 1? The solution of this old problem is now known as the (classical) isoperimetric inequality, namely, the minimal area is attained at and only at Euclidean balls with volume 1. The isoperimetric inequality is an extremely powerful tool in geometry and related areas. Note that the classical isoperimetric inequality does not have the "affine invariant" flavor, because the area may change under linear transformations (even) with unit (absolute value of) determinant.However, many objects in (affine) convex geometry are invariant under invertible linear transformations. A typical example is the Mahler volume product M(K) = |K||K• |, the product of the volume of K and its polar body K• . That is, M(K) = M(T K) for all invertible linear transformations T on R n . One can ask a question for M(K) similar * Keywords: affine surface area, L p affine surface area, geominimal surface area, L p geominimal surface area, L p -Brunn-Minkowski theory, affine isoperimetric inequalities, the Blaschke-Santaló inequality, the Bourgain-Milman inverse Santaló inequality.