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The convergence and uniqueness of a discrete-time nonlinear Markov chain 离散非线性马尔可夫链的收敛性和唯一性
IF 1.6 2区 数学 Q1 MATHEMATICS Pub Date : 2026-01-22 DOI: 10.1016/j.jfa.2026.111367
Ruowei Li , Florentin Münch
In this paper, we prove the convergence and uniqueness of a general discrete-time nonlinear Markov chain with specific conditions. The results have important applications in discrete differential geometry. First, we prove the discrete-time Ollivier Ricci curvature flow dn+1(1ακdn)dn converges to a constant curvature metric on a finite weighted graph. As shown in [30, Theorem 5.1], a Laplacian separation principle holds on a locally finite graph with nonnegative Ollivier curvature. We further prove that the Laplacian separation flow converges to the constant Laplacian solution and generalizes the result to nonlinear p-Laplace operators. Moreover, our results can also be applied to study the long-time behavior in the nonlinear Dirichlet forms theory and nonlinear Perron-Frobenius theory. Finally, we define the Ollivier Ricci curvature of the nonlinear Markov chain which is consistent with the classical Ollivier Ricci curvature, sectional curvature [5], coarse Ricci curvature on hypergraphs [14] and the modified Ollivier Ricci curvature for p-Laplace. We also establish the convergence results for the nonlinear Markov chain with nonnegative Ollivier Ricci curvature.
本文在特定条件下证明了一类广义离散非线性马尔可夫链的收敛性和唯一性。所得结果在离散微分几何中有重要的应用。首先,证明离散时间Ollivier Ricci曲率流dn+1在有限加权图上收敛于一个常曲率度量。如[30,定理5.1]所示,对于具有非负奥利维尔曲率的局部有限图,拉普拉斯分离原理成立。进一步证明了拉普拉斯分离流收敛于常数拉普拉斯解,并将结果推广到非线性p-拉普拉斯算子。此外,我们的结果也可以应用于非线性Dirichlet形式理论和非线性Perron-Frobenius理论的长时间行为研究。最后,我们定义了非线性马尔可夫链的Ollivier Ricci曲率,该曲率与经典的Ollivier Ricci曲率、截面曲率[5]、超图上的粗Ricci曲率[14]以及p-Laplace下的修正Ollivier Ricci曲率一致。我们还建立了具有非负曲率的非线性马尔可夫链的收敛性结果。
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引用次数: 0
Sharp ℓp inequalities for discrete singular integrals on the lattice Zd 晶格Zd上离散奇异积分的尖锐不等式
IF 1.6 2区 数学 Q1 MATHEMATICS Pub Date : 2026-01-22 DOI: 10.1016/j.jfa.2026.111359
Rodrigo Bañuelos , Daesung Kim , Mateusz Kwaśnicki
This paper investigates higher dimensional versions of the longstanding conjecture verified in [11] that the p-norm of the discrete Hilbert transform on the integers is the same as the Lp-norm of the Hilbert transform on the real line. It computes the p-norms of a family of discrete operators on the lattice Zd, d1. They are discretizations of a new class of singular integrals on Rd that have the same kernels as the classical Riesz transforms near zero and similar behavior at infinity. The discrete operators have the same p-norms as the classical Riesz transforms on Rd. They are constructed as conditional expectations of martingale transforms of Doob h-processes conditioned to exit the upper-half space Rd×R+ only on the lattice Zd. The paper also presents a discrete analogue of the classical method of rotations which gives the norm of a different variant of discrete Riesz transforms on Zd. Along the way a new proof is given based on Fourier transform techniques of the key identity used to identify the norm of the discrete Hilbert transform in [11]. Open problems are stated.
本文研究了[11]中证明的长时间猜想的高维版本,即整数上的离散希尔伯特变换的p-范数与实线上的希尔伯特变换的p-范数相同。它计算晶格Zd, d≥1上离散算子族的p-范数。它们是一类新的奇异积分在Rd上的离散化,它们与经典的Riesz变换在零附近有相同的核,在无穷远处有相似的行为。离散算子具有与Rd上的经典Riesz变换相同的p-范数。它们被构造为Doob h过程的鞅变换的条件期望,条件是只能在格Zd上退出上半部空间Rd×R+。本文还给出了经典旋转方法的离散模拟,给出了Zd上离散Riesz变换的不同变体的范数。在此过程中,基于傅里叶变换技术给出了用于识别[11]中离散希尔伯特变换范数的关键恒等式的一个新的证明。说明了尚未解决的问题。
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引用次数: 0
Index estimates for constant mean curvature surfaces in three-manifolds by energy comparison 用能量比较法估计三流形中常平均曲率曲面的指数
IF 1.6 2区 数学 Q1 MATHEMATICS Pub Date : 2026-01-22 DOI: 10.1016/j.jfa.2026.111375
Luca Seemungal, Ben Sharp
We prove a linear upper bound on the Morse index of closed constant mean curvature (CMC) surfaces in orientable three-manifolds in terms of genus, number of branch points and a Willmore-type energy.
利用属、分支点数和willmore型能量证明了可定向三流形中闭常平均曲率曲面的摩尔斯指数的线性上界。
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引用次数: 0
An isoperimetric inequality for lower order Neumann eigenvalues in Gauss space 高斯空间中低阶诺伊曼特征值的等周不等式
IF 1.6 2区 数学 Q1 MATHEMATICS Pub Date : 2026-01-22 DOI: 10.1016/j.jfa.2026.111379
Yi Gao, Kui Wang
We prove a sharp isoperimetric inequality for the harmonic mean of the first m1 nonzero Neumann eigenvalues for Lipschitz domains symmetric about the origin in Gauss space. Our result generalizes the Szegö-Weinberger type inequality in Gauss space, which was proven by Chiacchio and Di Blasio in [12, Theorem 4.1].
我们证明了高斯空间中关于原点对称的Lipschitz域的前m−1个非零诺伊曼特征值的调和平均值的尖锐等周不等式。我们的结果推广了高斯空间中由Chiacchio和Di Blasio在[12,定理4.1]中证明的Szegö-Weinberger型不等式。
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引用次数: 0
Degenerate or singular parabolic systems with partially DMO coefficients: the Dirichlet problem 具有部分DMO系数的退化或奇异抛物型系统:狄利克雷问题
IF 1.6 2区 数学 Q1 MATHEMATICS Pub Date : 2026-01-22 DOI: 10.1016/j.jfa.2026.111365
Hongjie Dong , Seongmin Jeon
In this paper, we study solutions u of parabolic systems in divergence form with zero Dirichlet boundary conditions in the upper-half cylinder Q1+Rn+1, where the coefficients are weighted by xnα, α(,1). We establish higher-order boundary Schauder type estimates of xnαu under the assumption that the coefficients have partially Dini mean oscillation. As an application, we also achieve higher-order boundary Harnack principles for degenerate or singular equations with Hölder continuous coefficients.
本文研究了上半圆柱体Q1+∧Rn+1中Dirichlet边界条件为零的发散型抛物型方程组的解u,其中系数用xnα, α∈(−∞,1)加权。在系数部分具有Dini平均振荡的假设下,建立了xnαu的高阶边界Schauder型估计。作为应用,我们也得到了具有Hölder连续系数的退化或奇异方程的高阶边界哈纳克原理。
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引用次数: 0
A note on the stability of self-similar blow-up solutions for superconformal semilinear wave equations 超共形半线性波动方程自相似爆破解的稳定性注记
IF 1.6 2区 数学 Q1 MATHEMATICS Pub Date : 2026-01-21 DOI: 10.1016/j.jfa.2026.111364
Jie Liu
In this note, we investigate the stability of self-similar blow-up solutions for superconformal semilinear wave equations in all dimensions. A central aspect of our analysis is the spectral equivalence of the linearized operators under Lorentz transformations in self-similar variables. This observation serves as a useful tool in proving mode stability and provides insights that may aid the study of self-similar solutions in related problems. As a direct consequence, we establish the asymptotic stability of the ODE blow-up family, extending the classical results of Merle and Zaag [45], [51] to the conformal and superconformal regimes and generalizing the recent work of Ostermann [52] to include the entire ODE blow-up family.
本文研究了超共形半线性波动方程自相似爆破解在所有维度上的稳定性。我们分析的一个中心方面是自相似变量中洛伦兹变换下线性化算子的谱等价性。这一观察结果是证明模态稳定性的有用工具,并提供了有助于研究相关问题中自相似解的见解。作为直接结果,我们建立了ODE爆破族的渐近稳定性,将Merle和Zaag[45],[51]的经典结果推广到共形和超共形区域,并将Ostermann[52]的最新工作推广到包括整个ODE爆破族。
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引用次数: 0
Conformal and extrinsic upper bounds for the harmonic mean of Neumann and Steklov eigenvalues Neumann和Steklov特征值调和平均值的共形和外在上界
IF 1.6 2区 数学 Q1 MATHEMATICS Pub Date : 2026-01-21 DOI: 10.1016/j.jfa.2026.111361
Hang Chen
Let M be an m-dimensional compact Riemannian manifold with boundary. We obtain the upper bounds of the harmonic mean of the first m nonzero Neumann eigenvalues and Steklov eigenvalues involving the conformal volume and relative conformal volume, respectively. We also give an optimal sharp extrinsic upper bound for closed submanifolds in space forms. These extend the previous related results for the first nonzero eigenvalues.
设M是一个有边界的M维紧致黎曼流形。我们分别得到了涉及共形体积和相对共形体积的前m个非零Neumann特征值和Steklov特征值的调和平均值的上界。我们还给出了空间形式的闭子流形的最优尖锐外部上界。这些扩展了先前关于第一个非零特征值的相关结果。
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引用次数: 0
Ryll-Wojtaszczyk formulas for bihomogeneous polynomials on the sphere 球上双齐次多项式的ryl - wojtaszczyk公式
IF 1.6 2区 数学 Q1 MATHEMATICS Pub Date : 2026-01-21 DOI: 10.1016/j.jfa.2026.111360
A. Defant , D. Galicer , M. Mansilla , M. Mastyło , S. Muro
We investigate projection constants for spaces of bihomogeneous harmonic and bihomogeneous polynomials on the unit sphere in finite-dimensional complex Hilbert spaces. Using averaging techniques, we demonstrate that the minimal norm projection aligns with the natural orthogonal projection. This result enables us to establish a connection between these constants and weighted L1-norms of specific Jacobi polynomials. Consequently, we derive explicit bounds, provide practical expressions for computation, and present asymptotically sharp estimates for these constants. Our findings extend the classical Ryll and Wojtaszczyk formula for the projection constant of homogeneous polynomials in finite-dimensional complex Hilbert spaces to the bihomogeneous setting.
研究了有限维复希尔伯特空间中单位球上双齐次调和多项式和双齐次多项式空间的投影常数。利用平均技术,我们证明了最小范数投影与自然正交投影对齐。这一结果使我们能够建立这些常数与特定雅可比多项式的加权l1范数之间的联系。因此,我们导出了显式边界,提供了实用的计算表达式,并给出了这些常数的渐近尖锐估计。我们的发现将有限维复希尔伯特空间中齐次多项式投影常数的经典Ryll和Wojtaszczyk公式推广到双齐次环境。
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引用次数: 0
The free boundary for a superlinear system 超线性系统的自由边界
IF 1.6 2区 数学 Q1 MATHEMATICS Pub Date : 2026-01-21 DOI: 10.1016/j.jfa.2026.111363
Daniela De Silva , Seongmin Jeon , Henrik Shahgholian
In this paper, we study superlinear systems that give rise to free boundaries. Such systems appear for example from the minimization of the energy functionalΩ(|u|2+2p|u|p),0<p<1, but solutions can be also understood in an ad hoc viscosity way.
First, we prove the optimal regularity of minimizers using a variational approach. Then, we apply a linearization technique to establish the C1,α-regularity of the “flat” part of the free boundary via a viscosity method. Finally, for minimizing free boundaries, we extend this result to analyticity.
本文研究了产生自由边界的超线性系统。例如,这样的系统出现在能量泛函∫Ω(|∇u|2+2p|u|p),0<p<;1的最小化中,但解也可以用一种特殊的粘度方式来理解。首先,我们用变分方法证明了最小值的最优正则性。然后,我们应用线性化技术,通过粘度法建立了自由边界“平坦”部分的C1,α-正则性。最后,对于最小化自由边界,我们将这一结果推广到可分析性。
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引用次数: 0
K-theory and structural properties of C⁎-algebras associated with relative generalized Boolean dynamical systems 与相对广义布尔动力系统相关的C -代数的k理论和结构性质
IF 1.6 2区 数学 Q1 MATHEMATICS Pub Date : 2026-01-21 DOI: 10.1016/j.jfa.2026.111348
Toke Meier Carlsen , Eun Ji Kang
We present an explicit formula for the K-theory of the C-algebra associated with a relative generalized Boolean dynamical system (B,L,θ,Iα;J). In particular, we find concrete generators for the K1-group of C(B,L,θ,Iα;J). We also prove that every gauge-invariant ideal of C(B,L,θ,Iα;J) is Morita equivalent to a C-algebra of a relative generalized Boolean dynamical system.
As a structural application, we show that if the underlying Boolean dynamical system (B,L,θ) satisfies Condition (K), then the associated C-algebra is K0-liftable. Furthermore, we deduce that if C(B,L,θ,Iα;J) is separable and purely infinite, then it has real rank zero.
我们给出了与相对广义布尔动力系统(B,L,θ,Iα;J)相关的C -代数的k理论的一个显式公式。特别地,我们找到了C _ (B,L,θ,Iα;J)的k1群的具体发生器。我们还证明了C (B,L,θ,Iα;J)的每一个规范不变理想都是Morita等价于一个相对广义布尔动力系统的C代数。作为一个结构应用,我们证明了如果底层布尔动力系统(B,L,θ)满足条件(K),则相关的C -代数是k0可举的。进一步,我们推导出,如果C - C (B,L,θ, i - α;J)是可分离的纯无限的,那么它的实秩为零。
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引用次数: 0
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Journal of Functional Analysis
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