Homotopy Posets, Postnikov Towers, and Hypercompletions of \infty-Categories

This paper extends fundamental homotopical concepts to (,)(\infty,\infty)-categories and presentable enriched categories by introducing homotopy posets indexed by categorical disk boundaries, which assemble into a Postnikov tower converging for (,n)(\infty,n)-categories and characterize Postnikov complete (,)(\infty,\infty)-categories as the limit of (,n)(\infty,n)-categories under truncation.

David Gepner, Hadrian HeineWed, 11 Ma🔢 math

Motivic Homotopy Groups of Spheres and Free Summands of Stably Free Modules

This paper establishes that motivic stable homotopy groups of spheres over an algebraically closed field of characteristic zero are determined by pp-completed spheres and motivic cohomology, enabling the proof that complex realization induces isomorphisms in specific bidegrees and resolving the conditions under which the universal stably-free module of type (n,n1)(n,n-1) admits a free summand.

Sebastian Gant, Ben WilliamsTue, 10 Ma🔢 math

On intersection cohomology with torus action of complexity one, II

This paper establishes that the decomposition theorem components for contraction maps of torus actions of complexity one are intersection cohomology complexes of even codimensional subvarieties, leading to the vanishing of odd-dimensional intersection cohomology for rational complete varieties of this type and providing explicit formulas for the Betti numbers of affine trinomial hypersurfaces based on their defining equations.

Marta Agustin Vicente, Narasimha Chary Bonala, Kevin LangloisTue, 10 Ma🔢 math

Theorem of the heart for Weibel's homotopy KK-theory

This paper establishes the theorem of the heart for Weibel's homotopy KK-theory (KHKH), proving that the realization functor induces an equivalence KH(C)KH(C)KH(\mathcal{C}^{\heartsuit}) \simeq KH(\mathcal{C}) for small stable \infty-categories with bounded tt-structures, a result derived from a strengthened version of Barwick's theorem that provides precise isomorphism ranges for classical KK-theory and demonstrates the sharpness of these bounds.

Alexander I. EfimovTue, 10 Ma🔢 math