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Graded $p$-polar rings and the homology of $Ω^nΣ^nX$

Tilman Bauer

TL;DR

The paper develops graded analogues of $p$-polar algebras and proves that free affine $p$-adic group schemes and free formal groups factor through graded $p$-polar algebras over a perfect field of characteristic $p$. It then constructs graded Witt and co-Witt vector theories and establishes graded Dieudonné correspondences to analyze unipotent and connected graded Hopf structures, enabling a functorial description of homological invariants. A key topological consequence is that the Hopf algebra $H^*(Ω^nΣ^n X; extbf{F}_p)$ depends only on the $p$-polar structure of $H^*(X; extbf{F}_p)$, linking graded polar data to iterated loop-space homology. Together, these results unify algebraic and topological perspectives on graded $p$-polar structures, providing refined control over the homology of free $E_n$-algebras and their loop-space cohomology via Witt–Dieudonné theory.

Abstract

As an extension of previous ungraded work, we define a graded $p$-polar ring to be an analog of a graded commutative ring where multiplication is only allowed on $p$-tuples (instead of pairs) of elements of equal degree. We show that the free affine $p$-adic group scheme functor, as well as the free formal group functor, defined on $k$-algebras for a perfect field $k$ of characteristic $p$, factors through $p$-polar $k$-algebras. It follows that the same is true for any affine $p$-adic or formal group functor, in particular for the functor of $p$-typical Witt vectors. As an application, we show that the homology of the free $E_n$-algebra $H^*(Ω^nΣ^n X;\mathbf F_p)$, as a Hopf algebra, only depends on the $p$-polar structure of $H^*(X;\mathbf F_p)$ in a functorial way.

Graded $p$-polar rings and the homology of $Ω^nΣ^nX$

TL;DR

The paper develops graded analogues of -polar algebras and proves that free affine -adic group schemes and free formal groups factor through graded -polar algebras over a perfect field of characteristic . It then constructs graded Witt and co-Witt vector theories and establishes graded Dieudonné correspondences to analyze unipotent and connected graded Hopf structures, enabling a functorial description of homological invariants. A key topological consequence is that the Hopf algebra depends only on the -polar structure of , linking graded polar data to iterated loop-space homology. Together, these results unify algebraic and topological perspectives on graded -polar structures, providing refined control over the homology of free -algebras and their loop-space cohomology via Witt–Dieudonné theory.

Abstract

As an extension of previous ungraded work, we define a graded -polar ring to be an analog of a graded commutative ring where multiplication is only allowed on -tuples (instead of pairs) of elements of equal degree. We show that the free affine -adic group scheme functor, as well as the free formal group functor, defined on -algebras for a perfect field of characteristic , factors through -polar -algebras. It follows that the same is true for any affine -adic or formal group functor, in particular for the functor of -typical Witt vectors. As an application, we show that the homology of the free -algebra , as a Hopf algebra, only depends on the -polar structure of in a functorial way.
Paper Structure (10 sections, 30 theorems, 76 equations)

This paper contains 10 sections, 30 theorems, 76 equations.

Key Result

Theorem 1.1

Let $k$ be a perfect field of characteristic $p$. Then the forgetful functors $\operatorname{AbSch}_{k}^p \to \mathop{\mathrm{Alg}}\nolimits_k^{{\operatorname{op}}}$ resp. $\operatorname{Fgps}_{k} \to (\mathop{\mathrm{Pro}}\nolimits-\mathop{\mathrm{alg}}\nolimits_k)^{{\operatorname{op}}}$ have left

Theorems & Definitions (75)

  • Definition
  • Theorem 1.1
  • Corollary 1.2
  • proof
  • Definition
  • Lemma 1.3
  • Theorem 1.4
  • Theorem 1.5
  • Theorem 1.6
  • Theorem 1.7
  • ...and 65 more