No Arabic abstract
A qualgebra $G$ is a set having two binary operations that satisfy compatibility conditions which are modeled upon a group under conjugation and multiplication. We develop a homology theory for qualgebras and describe a classifying space for it. This space is constructed from $G$-colored prisms (products of simplices) and simultaneously generalizes (and includes) simplicial classifying spaces for groups and cubical classifying spaces for quandles. Degenerate cells of several types are added to the regular prismatic cells; by duality, these correspond to non-rigid Reidemeister moves and their higher dimensional analogues. Coupled with $G$-coloring techniques, our homology theory yields invariants of knotted trivalent graphs in $mathbb{R}^3$ and knotted foams in $mathbb{R}^4$. We re-interpret these invariants as homotopy classes of maps from $S^2$ or $S^3$ to the classifying space of $G$.
We define, for each quasi-syntomic ring $R$ (in the sense of Bhatt-Morrow-Scholze), a category $mathrm{DF}(R)$ of textit{filtered prismatic Dieudonne crystals over $R$} and a natural functor from $p$-divisible groups over $R$ to $mathrm{DF}(R)$. We prove that this functor is an antiequivalence. Our main cohomological tool is the prismatic formalism recently developed by Bhatt and Scholze.
We compute the Chern subgroup of the 4-th integral cohomology group of a certain classifying space and show that it is a proper subgroup. Such a classifying space gives us new counterexamples for the integral Hodge and Tate conjectures modulo torsion.
In this chapter, we survey the algebraic aspects of quantum Teichmuller space, generalized Kashaev algebra and a natural relationship between the two algebras.
We prove that the every quasi-isometry of Teichmuller space equipped with the Teichmuller metric is a bounded distance from an isometry of Teichmuller space. That is, Teichmuller space is quasi-isometrically rigid.
We answer the question of when the underlying space of an orbifold is a manifold with boundary in several categories.