Local and local-to-global Principles for zero-cycles on geometrically Kummer K3K3 surfaces

This paper proves a conjecture by Raskind, Spiess, Colliot-Thélène, and Sansuc regarding the structure of the Chow group of zero-cycles on geometrically Kummer K3K3 surfaces over pp-adic fields and provides the first unconditional evidence for a local-to-global principle for zero-cycles on such surfaces by demonstrating that the Brauer-Manin obstruction is the sole obstruction to weak approximation in specific cases.

Evangelia Gazaki, Jonathan LoveTue, 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

Introduction to non-Abelian Patchworking

This paper introduces the framework of non-Abelian patchworking, a geometric method for constructing real algebraic surfaces in RP3\mathbb{R}P^3 via the real locus of non-Abelian complex-phase tropical hypersurfaces, which successfully reproduces all isotopy types of surfaces up to degree three and reveals that primitive PGL2PGL_2 surfaces can exhibit Euler characteristics distinct from their complex counterparts.

Turgay Akyar, Mikhail ShkolnikovTue, 10 Ma🔢 math