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Hansheng Diao

Publications and source records attributed to Hansheng Diao.

17 recordsLinked to original sources

A $p$-adic monodromy theorem for curves

We prove that every de Rham $p$-adic local system on a smooth projective curve over a $p$-adic field is potentially semistable; that is, it becomes semistable after pulling back along a finite cover of the curve. This establishes a relative version of the classical $p$-adic monodromy theorem of Berger and André--Kedlaya--Mebkhout. Along the way, we also establish a $p$-adic monodromy theorem for de Rham $p$-adic local systems on disks and annuli.

math.NT

Relative $(φ, Γ)$-modules and $p$-adic differential equations

Let $X$ be an affinoid rigid analytic space over a $p$-adic field, equipped with a suitable étale map to a unit polydisk. We provide a formalism of \emph{imperfect relative period rings} over $X$, which lie inside the corresponding perfect relative period rings constructed by Kedlaya--Liu. Then we establish a relative version of the Fontaine--Cherbonnier--Colmez equivalence between $p$-adic local systems on $X$ and étale $(φ, Γ)$-modules over such imperfect relative period rings, generalizing previous works of Andreatta--Brinon and others. Using this equivalence, we construct $p$-adic differential equations attached to de Rham local systems, carrying both geometric and arithmetic differential operators. This generalizes the work of Berger to the relative geometric setting. Along the way, we study a relative Fontaine--Sen theory on the decompletion of $Γ$-modules over the relative $\mathbf{B}_{\mathrm{dR}}^+$-period rings.

math.NT

Logarithmic $A_{\mathrm{inf}}$-cohomology, Part II

We develop a theory of logarithmic $A_{\mathrm{inf}}$-cohomology with coefficients for a class of $p$-adic log formal schemes that are ``sufficiently log smooth'', where the coefficients are given by relative log BKF modules. Then we establish comparison isomorphisms with étale, de Rham, and crystalline cohomology, and also extend these results to the derived setting. As an application, we give a new proof of the $C_{\mathrm{st}}$ conjecture for semistable local systems. The proof also uses the prismatic interpretation of semistable local systems established by Du--Liu--Moon--Shimizu.

math.AG

Perfectoid overconvergent Siegel modular forms and the overconvergent Eichler--Shimura morphism

The aim of this paper is twofold. We first present a construction of the overconvergent automorphic sheaves for Siegel modular forms by generalising the perfectoid method, originally introduced by Chojecki--Hansen--Johansson for automorphic forms on compact Shimura curves over $\mathbf{Q}$. The global sections of these automorphic sheaves are precisely the overconvergent Siegel modular forms. In particular, one can compare these automorphic sheaves with the ones constructed by Andreatta--Iovita--Pilloni. Secondly, we establish an (explicit) overconvergent Eichler--Shimura morphism for Siegel modular forms, generalising the result of Andreatta--Iovita--Stevens for the elliptic modular forms.

math.NT

Monodromy and rigidity of crystalline local systems

We study several rigidity properties of $p$-adic local systems on a smooth rigid analytic space $X$ over a $p$-adic field. We prove that the monodromy of the log isocrystal attached to a $p$-adic local system is ''rigid'' along irreducible components of the special fiber. Then we give several applications. First, suppose that $X$ has good reduction. We show that if a family of semistable representations is crystalline at one classical point on $X$, then it is crystalline everywhere. Second, combining with the $p$-adic monodromy theorem recently studied by the authors and their collaborators, we prove the following surprising rigidity result conjectured by Shankar: for any $p$-adic local system on a smooth projective variety with good reduction, if it is potentially crystalline at one classical point, then it is potentially crystalline everywhere. Finally, we show that if a $p$-adic local system on the complement of a reduced normal crossing divisor on a smooth rigid analytic space is crystalline at all classical points, then it extends uniquely to a $p$-adic local system on the entire space. In other words, such a local system cannot have geometric monodromy if it has no arithmetic monodromy everywhere on the complement of a reduced normal crossing divisor.

math.AG

Overconvergent Eichler-Shimura morphisms for $\mathrm{GSp}_4$

We construct explicit Eichler-Shimura morphisms for families of overconvergent Siegel modular forms of genus two. These can be viewed as $p$-adic interpolations of the Eichler-Shimura decomposition of Faltings-Chai for classical Siegel modular forms. In particular, we are able to $p$-adically interpolate the entire decomposition, extending our previous work on the $H^0$-part. The key new inputs are the higher Coleman theory of Boxer-Pilloni and a theory of pro-Kummer étale cohomology with supports.

math.NT

Logarithmic A$_{\rm inf}$-cohomology

We extend the construction of A$_{\rm inf}$-cohomology by Bhatt-Morrow-Scholze to the context of log $p$-adic formal schemes over a log perfectoid base. In particular, using coordinates, we prove comparison theorems between log A$_{\rm inf}$-cohomology with other $p$-adic cohomology theories, including log de Rham, log (q-)crystalline, log prismatic, and Kummer étale cohomology, as well as the derived A$_{\rm inf}$-cohomology of certain infinite root stacks. Along the way, we define and give a combinatorial characterization of a new class of maps between saturated log schemes, called pseudo-saturated maps, which is of independent interest. They are related to (and slightly weaker than) the notion of quasi-saturated maps and maps of Cartier type studied by Tsuji.

math.NT

The Halo Conjecture for GL2

We prove the Halo conjecture on the geometry of the eigencurve over the boundary of the weight space, predicted by Coleman-Mazur and Buzzard-Kilford.

math.NT

Logarithmic Riemann-Hilbert correspondences for rigid varieties

On any smooth algebraic variety over a $p$-adic local field, we construct a tensor functor from the category of de Rham $p$-adic étale local systems to the category of filtered algebraic vector bundles with integrable connections satisfying the Griffiths transversality, which we view as a $p$-adic analogue of Deligne's classical Riemann--Hilbert correspondence. A crucial step is to construct canonical extensions of the desired connections to suitable compactifications of the algebraic variety with logarithmic poles along the boundary, in a precise sense characterized by the eigenvalues of residues; hence the title of the paper. As an application, we show that this $p$-adic Riemann--Hilbert functor is compatible with the classical one over all Shimura varieties, for local systems attached to representations of the associated reductive algebraic groups.

math.AG

Logarithmic adic spaces: some foundational results

We develop a theory of log adic spaces by combining the theories of adic spaces and log schemes, and study the Kummer étale and pro-Kummer étale topology for such spaces. We also establish the primitive comparison theorem in this context, and deduce from it some related cohomological finiteness or vanishing results.

math.AG

Foundations of Logarithmic Adic Spaces

The main objects of study are adic spaces with logarithmic structures. After establishing the basic definitions, we analyze the Kummer étale and pro-Kummer étale topologies on log adic spaces. In particular, we show that log adic spaces are locally "log affinoid perfectoid" in the pro-Kummer étale topology. As an application, we prove finiteness of cohomologies for Kummer étale $\mathbb{F}_p$-local systems on proper log smooth adic spaces.

math.NT

The Eigencurve is Proper

We prove that the Coleman-Mazur eigencurve is proper over the weight space for any prime p and tame level N.

math.NT

Measurable Time-Restricted Sensitivity

We develop two notions of time-restricted sensitivity to initial conditions for measurable dynamical systems, where the time before divergence of a pair of paths is at most an asymptotically logarithmic function of a measure of their initial distance. In the context of finite measure-preserving transformations on a compact space, we relate these notions to the metric entropy of the system. We examine one of these notions for classes of non-measure-preserving, nonsingular transformations.

math.DS

Digraph Representations Of Rational Functions Over $p$-adic Numbers

In this paper, we construct a digraph structure on $p$-adic dynamical systems defined by rational functions. We study the conditions under which the functions are measure-preserving, invertible and isometric, ergodic, and minimal on invariant subsets, by means of graph theoretic properties.

math.DS

Freiman-Ruzsa-type theory for small doubling constant

In this paper, we study the linear structure of sets $A \subset \mathbb{F}_2^n$ with doubling constant $σ(A)<2$, where $σ(A):=\frac{|A+A|}{|A|}$. In particular, we show that $A$ is contained in a small affine subspace. We also show that $A$ can be covered by at most four shifts of some subspace $V$ with $|V|\leq |A|$. Finally, we classify all binary sets with small doubling constant.

math.CO

A poset structure on quasifibonacci partitions

In this paper, we study partitions of positive integers into distinct quasifibonacci numbers. A digraph and poset structure is constructed on the set of such partitions. Furthermore, we discuss the symmetric and recursive relations between these posets. Finally, we prove a strong generalization of Robbins' result on the coefficients of a quasifibonacci power series.

math.CO