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Zhilin Luo

Publications and source records attributed to Zhilin Luo.

12 recordsLinked to original sources
arXiv2026

Relative Dolbeault Geometric Langlands via the Regular Quotient

Let $X = G/H$ be an affine homogeneous spherical variety with abelian regular centralizer and no type N roots. In this paper, we formulate a relative geometric Langlands conjecture in the Dolbeault setting for $M = T^*X$. More concretely, we conjecture a Fourier-Mukai duality between the Dolbeault period sheaf and a sheaf whose construction closely resembles the Dirac-Higgs bundle of a polarization of the dual symplectic representation of Ben-Zvi, Sakellaridis, and Venkatesh. These conjectures can be seen as a generalization of Hitchin's conjectural duality of branes for symmetric spaces. We verify these conjectures in several cases, including the Friedberg-Jacquet case $X = GL_{2n}/GL_n\times GL_n$, the Jacquet-Ichino case $X = PGL_2^3/PGL_2$, the Rankin-Selberg case $X = GL_n\times GL_{n+1}/GL_n$, and the Gross-Prasad case $X = SO_n\times SO_{n+1}/SO_n$. Our main tool is the theory of the regular quotient, which was described in the context of symmetric spaces in [HM24].

math.AG↗
arXiv2024

Nonabelian Fourier Kernels on $\mathrm{SL}_2$ and $\mathrm{GL}_2$

For $G=\mathrm{SL}_2$ or $\mathrm{GL}_2$, we present explicit formulas for the nonabelian Fourier kernels on $G$, as conjectured by A. Braverman and D. Kazhdan. Additionally, we furnish explicit formulas for the orbital Hankel transform on $G$, a topic investigated by the second author, and provide an explicit formula for the stable orbital integral of the basic function. These results are applicable to local fields with residual characteristics other than two.

math.NT↗
arXiv2022

Bias of Root Numbers for Hilbert Newforms of Cubic Level

We give a general formula of the bias of root numbers for Hilbert modular newforms of cubic level. Explicit calculation is given when the base field is $\mathbb{Q}, \mathbb{Q}(\sqrt{2}), \mathbb{Q}(\sqrt{5})$ and the level is the cube of certain rational integers. This complements a previous result of the second author and extends the bias phenomenon to the number fields. Our method is based on Jacquet-Zagier's trace formula, and the explicit calculation works generally for all real quadratic fields of narrow class number one and for rational cubic levels.

math.NT↗
arXiv2022

Certain Fourier Operators on $\mathrm{GL}_1$ and Local Langlands Gamma functions

For a split reductive group $G$ over a number field $k$, let $ρ$ be an $n$-dimensional complex representation of its complex dual group $G^\vee(\mathbb{C})$. For any irreducible cuspidal automorphic representation $σ$ of $G(\mathbb{A})$, where $\mathbb{A}$ is the ring of adeles of $k$, in \cite{JL21}, the authors introduce the $(σ,ρ)$-Schwartz space $\mathcal{S}_{σ,ρ}(\mathbb{A}^\times)$ and $(σ,ρ)$-Fourier operator $\mathcal{F}_{σ,ρ}$, and study the $(σ,ρ,ψ)$-Poisson summation formula on $\mathrm{GL}_1$, under the assumption that the local Langlands functoriality holds for the pair $(G,ρ)$ at all local places of $k$, where $ψ$ is a non-trivial additive character of $k\backslash\mathbb{A}$. Such general formulae on $\mathrm{GL}_1$, as a vast generalization of the classical Poisson summation formula, are expected to be responsible for the Langlands conjecture (\cite{L70}) on global functional equation for the automorphic $L$-functions $L(s,σ,ρ)$. In order to understand such Poisson summation formulae, we continue with \cite{JL21} and develop a further local theory related to the $(σ,ρ)$-Schwartz space $\mathcal{S}_{σ,ρ}(\mathbb{A}^\times)$ and $(σ,ρ)$-Fourier operator $\mathcal{F}_{σ,ρ}$. More precisely, over any local field $k_ν$ of $k$, we define distribution kernel functions $k_{σ_ν,ρ,ψ_ν}(x)$ on $\mathrm{GL}_1$ that represent the $(σ_ν,ρ)$-Fourier operators $\mathcal{F}_{σ_ν,ρ,ψ_ν}$ as convolution integral operators, i.e. generalized Hankel transforms, and the local Langlands $γ$-functions $γ(s,σ_ν,ρ,ψ_ν)$ as Mellin transform of the kernel function. As consequence, we show that any local Langlands $γ$-functions are the gamma functions in the sense of Gelfand, Graev, and Piatetski-Shapiro in \cite{GGPS}.

math.RT↗
arXiv2021

Certain Fourier Operators and their Associated Poisson Summation Formulae on $\mathrm{GL}_1$

In this paper, we explore a possibility to utilize harmonic analysis on $\GL_1$ to understand Langlands automorphic $L$-functions in general, as a vast generalization of the pioneering work of J. Tate. For a split reductive group $G$ over a number field $k$, let $G^\vee(\BC)$ be its complex dual group and $ρ$ be an $n$-dimensional complex representation of $G^\vee(\BC)$. For any irreducible cuspidal automorphic representation $\sig$ of $G(\BA)$, where $\BA$ is the ring of adeles of $k$, we introduce the space $\CS_{\sig,ρ}(\BA^\times)$ of $(\sig,ρ)$-Schwartz functions on $\BA^\times$ and $(\sig,ρ)$-Fourier operator $\CF_{\sig,ρ,ψ}$ that takes $\CS_{\sig,ρ}(\BA^\times)$ to $\CS_{\wt{\sig},ρ}(\BA^\times)$, where $\wt{\sig}$ is the contragredient of $\sig$. By assuming the local Langlands functoriality for the pair $(G,ρ)$, we show that the $(\sig,ρ)$-theta functions \[ Θ_{\sig,ρ}(x,ϕ):=\sum_{\alp\in k^\times}ϕ(\alp x) \] converges absolutely for all $ϕ\in\CS_{\sig,ρ}(\BA^\times)$, and state conjectures on $(σ,ρ)$-Poisson summation formula on $\GL_1$. Then we prove conjectures when $G=\GL_n$ and $ρ$ is the standard representation of $\GL_n(\BC)$ . The proof uses substantially the local theory of Godement-Jacquet for the standard $L$-functions of $\GL_n$ and the Poisson summation formula for the classical Fourier transform on affine spaces. As an application, we provide a spectral interpretation of the critical zeros of the standard $L$-functions $L(s,π\timesχ)$ for any irreducible cuspidal automorphic representation $π$ of $\GL_n(\BA)$ and idele class character $χ$ of $k$, which is a reformulation in the adelic framework of the work of A. Connes and is an extension from the Hecke $L$-functions $L(s,χ)$ to the automorphic $L$-functions $L(s,π\timesχ)$.

math.RT↗
arXiv2021

Harmonic Analysis and Gamma Functions on Symplectic Groups

Over a $p$-adic local field $F$ of characteristic zero, we develop a new type of harmonic analysis on an extended symplectic group $G={\mathbb G}_m\times{\mathrm Sp}_{2n}$. It is associated to the Langlands $γ$-functions attached to any irreducible admissible representations $χ\otimesπ$ of $G(F)$ and the standard representation $ρ$ of the dual group $G^\vee({\mathbb C})$, and confirms a series of the conjectures in the local theory of the Braverman-Kazhdan proposal for the case under consideration. Meanwhile, we develop a new type of harmonic analysis on ${\rm GL}_1(F)$, which is associated to a $γ$-function $β_ψ(χ_s)$ (a product of $n+1$ certain abelian $γ$-functions). Our work on ${\rm GL}_1(F)$ plays an indispensable role in the development of our work on $G(F)$. These two types of harmonic analyses both specialize to the well-known local theory developed in Tate's thesis when $n=0$. The approach is to use the compactification of ${\rm Sp}_{2n}$ in the Grassmannian variety of ${\rm Sp}_{4n}$, with which we are able to utilize the well developed local theory of Piatetski-Shapiro and Rallis and many other works) on the doubling local zeta integrals for the standard $L$-functions of ${\rm Sp}_{2n}$. The method can be viewed as an extension of the work of Godement-Jacquet for the standard $L$-function of ${\rm GL}_n$ and is expected to work for all classical groups. We will consider the archimedean local theory and the global theory in our future work.

math.NT↗
arXiv2020

A Local Trace Formula for the Local Gan-Gross-Prasad Conjecture for Special Orthogonal Groups

Through combining the work of Jean-Loup Waldspurger (\cite{waldspurger10} and \cite{waldspurgertemperedggp}) and Raphaël Beuzart-Plessis (\cite{beuzart2015local}), we give a proof for the tempered part of the local Gan-Gross-Prasad conjecture (\cite{ggporiginal}) for special orthogonal groups over any local fields of characteristic zero, which was already proved by Waldspurger over $p$-adic fields.

math.RT↗
arXiv2020

On the Stable Transfer for $\mathrm{Sym}^{n}$ Lifting of $\mathrm{GL}_{2}$

Following the paradigm of \cite{MR3117742}, we are going to explore the stable transfer factors for $\mathrm{Sym}^{n}$ lifting from $\mathrm{GL}_{2}$ to $\mathrm{GL}_{n+1}$ over any local fields $F$ of characteristic zero with residue characteristic not equal to $2$. When $F=\mathbb{C}$ we construct an explicit stable transfer factor for any $n$. When $n$ is odd, we provide a reduction formula, reducing the question to the construction of the stable transfer factors when the $L$-morphism is the diagonal embedding from $\mathrm{GL}_{2}(\mathbb{C})$ to finitely many copies of $\mathrm{GL}_{2}(\mathbb{C})$ under mild assumptions on the residue characteristic of $F$. With the assumptions on the residue characteristic, the reduction formula works uniformly over any local fields of characteristic zero, except that for $p$-adic situation we need to exclude the twisted Steinberg representations.

math.RT↗
arXiv2018

On the Braverman-Kazhdan Proposal for Local Factors: Spherical Case

In this paper, we study the Braverman-Kazhdan proposal for the local spherical situation. In the $p$-adic case, we give a definition of the spherical component of conjectural space $S_ρ(G,K)$ and the $ρ$-Fourier transform kernel $Φ^{K}_ρ$, and verify several conjectures in [BK00] in this situation. In the archimedean case, we study the asymptotic of the basic function $1_{ρ,s}$ and the $ρ$-Fourier transform kernel $Φ^{K}_{ρ,s}$.

math.NT↗
arXiv2015

On Maximum Norm of Exterior Product and A Conjecture of C.N. Yang

Let $V$ be a finite dimensional inner product space over $\mathbb{R}$ with dimension $n$, where $n\in \mathbb{N}$, $\wedge^{r}V$ be the exterior algebra of $V$, the problem is to find $\max_{\| ξ\| = 1, \| η\| = 1}\| ξ\wedge η\|$ where $k,l$ $\in \mathbb{N},$ $\forall ξ\in \wedge^{k}V, η\in \wedge^{l}V.$ This is a problem suggested by the famous Nobel Prize Winner C.N. Yang. He solved this problem for $k\leq 2$ in [1], and made the following \textbf{conjecture} in [2] : If $n=2m$, $k=2r$, $l=2s$, then the maximum is achieved when $ξ_{max} = \frac{ω^{k}}{\| ω^{k}\|}, η_{max} = \frac{ω^{l}}{\| ω^{l}\|}$, where $ ω= Σ_{i=1}^m e_{2i-1}\wedge e_{2i}, $ and $\{e_{k}\}_{k=1}^{2m}$ is an orthonormal basis of V. From a physicist's point of view, this problem is just the dual version of the easier part of the well-known Beauzamy-Bombieri inequality for product of polynomials in many variables, which is discussed in [4]. Here the duality is referred as the well known Bose-Fermi correspondence, where we consider the skew-symmetric algebra(alternative forms) instead of the familiar symmetric algebra(polynomials in many variables) In this paper, for two cases we give estimations of the maximum of exterior products, and the Yang's conjecture is answered partially under some special cases.

math-ph↗