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1. 非紧流形上Morrey空间中的Navier-Stokes方程适定性研究
Well-posedness for the Navier-Stokes equations in Morrey spaces on non-compact manifolds
作者: Víctor Chaves-Santos, Lucas C. F. Ferreira
类别: math.AP
发布日期: 2026-03-19
arXiv ID: 2603.19102v1
摘要翻译: 我们在一类非紧黎曼流形的Morrey空间框架内分析不可压缩Navier-Stokes方程。在假设有界几何及负里奇曲率与截面曲率(例如双曲空间)的条件下,我们建立了与Beltrami、Bochner和Hodge拉普拉斯算子相关的热半群在Morrey空间中的频散估计与光滑估计,以及里斯变换的相应估计。特别地,负曲率的存在带来了相较于欧氏情形更优的大时间衰减性。这些估计本身具有独立价值,并使我们得以在加藤型时间加权空间中构造解,从而在广泛的一类非紧流形上获得局部时间适定性,并在爱因斯坦流形情形下得到全局适定性。在后一种情形中,我们假设初值在弱于$L^{p}$范数的Morrey范数下满足小性条件,从而允许某些大$L^{p}$初值类。我们还讨论了结果到里奇平坦流形的推广。本研究为流形上的Navier-Stokes方程引入了一类新的非衰减且不光滑的初值,将此前在Lebesgue空间与Sobolev空间中的工作进行了推广。
Comment: 无
链接: http://arxiv.org/abs/2603.19102v1
1. 研究对象和背景
本文研究定义在光滑、完备、单连通且无边界的三维及以上非紧Riemann流形上的不可压缩Navier-Stokes方程,其几何背景假设流形具有有界几何结构以及负的Ricci曲率和截面曲率(例如双曲空间)。方程的具体形式为 $\partial_t u - \nu \Delta u + r(u) - B(u) = -P(\nabla_u u)$,其中涉及Beltrami拉普拉斯算子、Bochner拉普拉斯算子及其对应的曲率项 $r(u)$。以往关于该方程在流形上的研究主要集中在Lebesgue空间和Sobolev空间,例如Pierfelice利用能量方法在 $L^p$ 空间中建立了热核估计和适定性结果。然而,Morrey空间由于其对局部奇异性及非衰减行为的敏感性,为分析粗糙或具有无穷多奇点的初始数据提供了更精细的框架。本文首次将Morrey空间理论系统应用于非紧流形上的Navier-Stokes方程,并利用负曲率带来的指数衰减优势,扩展了经典结果。
2. 主要定理或主要结果
本文的核心成果包括一系列半群估计定理和适定性定理。在半群估计方面,首先在定理4.1、4.2和4.3中建立了Beltrami热半群 $e^{t\Delta_g}$ 在Morrey空间中的有界性,包括从 $M^{g}_{p,\lambda}$ 到 $L^\infty$、从 $M^{g}_{p,\lambda}$ 到自身,以及跨指数映射 $M^{g}_{p,\lambda} \to M^{g}_{q,\lambda}$。定理5.1进一步在负Ricci曲率假设下,将结果推广到Bochner热半群 $e^{t(\Delta + r)}$。定理5.2和5.3则分别建立了梯度算子 $\nabla e^{t\Delta_g}$ 和 $\nabla e^{t(\Delta + r)}$ 的平滑估计。定理6.1证明了Riesz变换 $\nabla(-\Delta_g)^{-1/2}$ 在Morrey空间中的有界性。在适定性方面,定理7.1针对一大类非紧流形,通过构造Kato型时间加权空间 $X_{T}^{b}$,在初始数据 $u_0 \in M^{g}_{p,\lambda}$ 且满足一定小性条件时,证明了解的局部存在唯一性。定理7.3在流形为Einstein流形(且具负曲率)时,在更弱的Morrey范数小性条件下,获得全局适定性。定理7.2则讨论了粘性修正模型的全局适定性。最后,在8节中,针对Ricci平坦流形,定理8.2、8.3、8.4分别建立了热半群、梯度估计和Riesz变换的有界性(需结合有界几何或大体积增长假设),定理8.5在此基础上证明了全局适定性。
3. 研究方法、关键技术和核心工具
研究方法的核心是建立热半群及其梯度在Morrey空间中的有界性,以此作为分析非线性项的基石。关键技术包括:(1)利用Bishop体积比较定理对非紧流形上测地球体积进行上下界估计(第2节),特别处理负曲率下的指数增长和小半径下的多项式增长;(2)引用并改进热核点态估计(如Davies、Grigor’yan的结果),结合Morrey范数的定义 $\|f\|_{g,p,\lambda} = \sup_{x_0, R} A(x_0, R)^{-\lambda/m} \|f\|_{L^p(B_{x_0}(R))}$,分别处理小半径 $R \le 1$ 和大半径 $R > 1$ 的情形;(3)通过 carefully 估计积分,将热核的指数衰减(来自负曲率)转化为Morrey范数控制,这比欧氏空间的多项式衰减更强;(4)引入时间加权空间 $X_T^b = \{ u \in L^\infty_{\text{loc}}((0,T), M^{g}_{q,\lambda}): d(t)^{m-1/2} t^{-\lambda/2} p^{1/q} e^{\beta t} \|u(t)\|_{g,q,\lambda} \in L^\infty(0,T) \}$,其中 $d(t)=\min\{1,t\}$,$\beta$ 与半群的衰减率匹配,并通过压缩映射原理证明局部解;(5)利用Morrey空间严格包含 $L^p$ 的性质(Lemma 3.3构造了如 $r(\cdot,y)^{-\eta} e^{-kr(\cdot,y)}$ 属于 $M^{g}_{p,\lambda}$ 但不属于 $L^p$ 的例子),使得在Einstein流形上的小性条件能够覆盖某些“大” $L^p$ 数据。工具上依赖微分几何中的体积估计、热核理论、调和分析中的Riesz变换有界性以及Banach空间不动点定理。
4. 与之前工作的比较
与既有文献相比,本文的贡献主要体现在以下几个方面:首先,在空间设置上,之前关于非紧流形上Navier-Stokes方程的工作(如Pierfelice [35])主要基于Lebesgue空间 $L^p$,而本文首次系统将其置于Morrey空间框架,从而能够处理具有局部奇异性或非衰减的初始数据(Lemma 3.3),扩展了可容许数据类。其次,在几何假设上,本文明确要求有界几何与负的Ricci及截面曲率,这比仅假设有界Ricci曲率的条件更强,但直接带来了热核的指数衰减估计(定理4.3等),相比欧氏空间或非负曲率情况下的多项式衰减是一种改进,且该改进对全局适定性的证明至关重要。第三,在适定性结果上,对于Einstein流形,本文在定理7.3中使用的Morrey范数小性条件弱于 $L^p$ 小性,这意味着可以覆盖某些在 $L^p$ 中较大的数据,这是Lebesgue空间方法难以实现的。与紧流形上的Morrey空间研究(如Taylor [42])相比,非紧情形需要更精细的体积比较和衰减估计,几何效应更难控制。最后,本文还考虑了Ricci平坦流形(如Calabi-Yau流形、ALE流形),在定理8.5中结合大体积增长等额外假设,将结果扩展到此类重要几何结构,而此前相关讨论较少。总体而言,本文通过弥散与平滑估计的深入分析,在非紧、具有负曲率的几何背景下,将Morrey空间方法推广到Navier-Stokes方程,实现了对更广初始数据类的适定性理论。
2. 具界全变差的保测映射
Measure preserving maps with bounded total variation
作者: Stefano Bianchini, Luca Talamini
类别: math.AP, math.FA
发布日期: 2026-03-19
arXiv ID: 2603.18819v1
摘要翻译: 设 $\Omega\subset \mathbb R^d$ 为开集,$\varphi:\Omega\to \mathbb R$ 为分段仿射 Lipschitz 映射,且假设对几乎每个 $t>0$,映 $x\mapsto x+t\nabla\varphi(x)$ 均为单射。在 (J.-G. Liu, R.~L. Pego, Rigidly breaking potential flows and a countable Alexandrov theorem for polytopes, Pure Appl. Anal., 7(4), 2025) 中,作者猜想此类 $\varphi$ 必具局部凸性。本文在附加条件 $\nabla\varphi\in BV_{\rm loc}(\Omega)$ 下,针对更广泛的保测映射类证明了该结论。
Comment: 无
链接: http://arxiv.org/abs/2603.18819v1
1. 研究对象和背景
本文研究满足特定条件的映射的凸性问题,源于Liu和Pego在[LP25]中提出的猜想。考虑开集$\Omega \subset \mathbb{R}^d$上的分片仿射Lipschitz映射$\phi: \Omega \to \mathbb{R}$,并假设对于几乎每个$t > 0$,映射$x \mapsto x + t \nabla \phi(x)$在某个全测度集上是单射。在最优传输理论中,经典结果表明存在唯一的凸映射$\nabla \phi$满足质量传输条件,但[LP25]猜想上述更一般的测度保持条件也能强制映射局部凸。本文在附加假设$\nabla \phi \in BV_{\mathrm{loc}}(\Omega)$下证明该猜想,并推广到更广泛的测度保持映射类,即$W^{1,1}(\Omega)$中满足测度保持条件(MPC)的函数。背景涉及最优传输、BV函数理论以及凸分析,其中测度保持条件捕捉了映射在变换下保持 Lebesgue 测度的性质,而局部凸性与函数的 Hessian 正定性相关。
2. 主要定理或主要结果
本文的核心结果是定理2.3:设$\phi \in W^{1,1}(\Omega)$满足测度保持条件(MPC),且$\nabla \phi \in BV_{\mathrm{loc}}(\Omega; \mathbb{R}^d)$,则$\phi$在$\Omega$中局部凸。这直接蕴含了定理1.2,即对分片仿射Lipschitz映射在$\nabla \phi \in BV_{\mathrm{loc}}$下的凸性。关键中间结果是命题2.4:满足(MPC)的$\phi$是次谐和的,即对任意非负$\psi \in C_c^1(\Omega)$,有$\int_\Omega -\nabla \phi \cdot \nabla \psi \, dx \geq 0$,或等价地$\Delta \phi \geq 0$在分布意义下成立。次谐和性证明无需BV假设,而局部 convexity 则依赖于$\nabla \phi$的BV正则性,通过分析其导数的绝对连续部分和奇异部分,并利用次谐和性推出奇异部分正定且绝对连续部分为零。
3. 研究方法、关键技术和核心工具
证明分为两个主要步骤,结合BV理论和积分变换技巧。首先,证明次谐和性(命题2.4)在更一般的“expanding映射”框架下:对$T_t(x) = x + t\nabla \phi(x)$,定义$\rho_t = (T_t)_\sharp L^d|_\Omega$,expanding条件$\rho_t \leq L^d$保证对非负$\psi$有$\int \psi \, d\rho_t \leq \int \psi \, dL^d$。通过函数$g_\psi(t) = \int \psi \, d\rho_t$的Lipschitz性和导数计算,利用 dominated convergence 定理和测度不等式,得到$\int_\Omega \nabla \phi \cdot \nabla \psi \, dx \leq 0$,从而$\Delta \phi \geq 0$。关键技术包括$L^1$可积性、控制收敛和测度变换。
其次,证明局部凸性:利用$\nabla \phi \in BV_{\mathrm{loc}}$,将其梯度测度分解为绝对连续部分$D_a(\nabla \phi)$和奇异部分$D_s(\nabla \phi)$。对奇异部分,应用 Alberti 秩一定理,$D_s(\nabla \phi)$有形式$\lambda \mathbf{n} \otimes \mathbf{n} |D_s(\nabla \phi)|$,次谐和性推出$\lambda \geq 0$几乎处处,故$D_s(\nabla \phi)$是正定矩阵值测度。对绝对连续部分,使用 Lusin-Lipschitz 性质:对任意$\Lambda > 0$,存在 Lipschitz 函数$f_\Lambda$逼近$\nabla \phi$,使得$f_\Lambda = \nabla \phi$在几乎处处的集合$G_\Lambda$上。定义$T_\Lambda(x) = x + t f_\Lambda(x)$,利用面积公式和(MPC)推导出$|\det(\mathrm{Id} + t D_a(\nabla \phi)(x))| = 1$几乎处处,进而通过特征值分析得$D_a(\nabla \phi) = 0$。因此$D(\nabla \phi) = D_s(\nabla \phi) \geq 0$正定,等价于$\phi$局部凸。核心工具包括 BV 测度分解、Alberti 定理、Lusin 逼近和 Lipschitz 映射的面积公式。
此外,第4节提供基于最优传输的替代证明:定义$\mu_t = L^d|_\Omega$和$\nu_t = (T_t)_\sharp \mu_t$,利用 Brenier 极分解定理,$T_t = \nabla f_t \circ \Phi_t$,其中$\nabla f_t$是凸函数,$\Phi_t$测度保持。分析$h_t = (\nabla f_t - \mathrm{id})/t$在$L^2$中的收敛性,通过 Helmholtz 分解和 Wasserstein 距离估计,证明$h_t$强收敛到梯度投影,从而得$\Delta \phi \geq 0$。此方法涉及最优传输、Wasserstein 几何和凸优化技术,并 yield 非BV情况下的额外性质。
4. 与之前工作的比较
本文工作与[LP25]直接相关:[LP25]仅证明了在$\nabla \phi$连续(即$\nabla \phi \in C(\Omega; \mathbb{R}^d)$)时猜想成立,而本文通过引入$\nabla \phi \in BV_{\mathrm{loc}}$假设,将结果推广到更低正则性类,覆盖了包括分片光滑但梯度有跳跃的映射。BV假设目前是必要的,因为存在次谐和但梯度无界的反例(如 Poisson 方程的基本解),非BV情况仍是开放问题。与方法论上,[LP25]可能依赖连续性直接论证,而本文采用BV分解和测度论工具,处理梯度奇异性;第4节的最优传输证明则借鉴了[Bre91]的 Brenier 理论,提供了不同视角,并暗示在无BV假设时,映射可能有额外结构(如与凸函数的接近性)。整体上,本文巩固了测度保持条件与凸性的联系,扩展了最优传输和BV理论的应用边界。
3. 近似无压欧拉-泊松系统的大摩擦极限
Large friction limit of the almost pressureless Euler-Poisson system
作者: Xin Liu
类别: math.AP
发布日期: 2026-03-18
arXiv ID: 2603.18346v1
摘要翻译: 本研究旨在探讨在强摩擦极限下,具有排斥力的近似无压欧拉-泊松(EP)系统。通过证明在该极限下的全局稳定性,我们确立了EP系统及凯勒-塞格尔(KS)系统的唯一全局时间解,其中极限方程被证明为消耗型双曲线-椭圆型凯勒-塞格尔系统。在关于初始数据的适当假设下,我们建立了两个系统的全局适定性,特别地,在渐近极限过程中不产生奇性。此外,本文还讨论了一维含真空态的KS流的时间渐近行为。
Comment: 无
链接: http://arxiv.org/abs/2603.18346v1
1. 研究对象和背景
本研究聚焦于具有排斥力的大摩擦极限下几乎无压欧拉-泊松(Euler-Poison,EP)系统。该系统的数学表述包含三个核心方程:质量守恒方程 $\partial_t \rho + \text{div}(\rho u) = 0$,动量守恒方程 $\frac{1}{\epsilon}\partial_t (\rho u) + \text{div}(\rho u \otimes u) + \epsilon^\alpha \nabla p + \rho u + \rho \nabla \phi = 0$,以及电势方程 $-\Delta \phi = \rho - M$。其中 $\rho$ 表示密度,$u$ 表示速度,$\phi$ 表示电势,$p = \rho^\gamma$($\gamma > 1$)为压力势,$\alpha > 0$ 为固定参数,$M > 0$ 为常数背景电荷,$0 < \epsilon \ll 1$ 为小参数。当 $\epsilon \to 0$ 时,系统处于大摩擦、几乎无压状态。
此系统用于描述带电粒子在由背景电荷 $M$ 产生的电场中的等离子体动力学。论文通过时间尺度变换 $t = \tau/\epsilon$ 将系统重写,并形式地推导出当 $\epsilon \to 0$ 时的主导方程为双曲-椭圆型 Keller-Segel(KS)消耗型系统:$\partial_\tau \sigma - \text{div}(\sigma \nabla \psi) = 0$,$-\Delta \psi = \sigma - M$。该极限系统本身具有丰富的数学结构:当 $\sigma > 0$ 时,平衡态 $\sigma_{e,1} = M$ 是全局稳定的;而真空态 $\sigma_{e,2} = 0$ 则是不稳定的。这种特性深刻影响了原问题在真空状态下的行为。
2. 主要定理或主要结果
论文的核心结果包括三个部分:一致正则性估计、大摩擦极限收敛性以及一维流的特殊分析。
定理1.3(一致正则性)建立了系统在 $\epsilon$ 一致意义下的能量估计。首先,在假设初始数据满足一定的有界性和可积性条件(公式(1.10)-(1.12))下,对于任意 $0 < \alpha < 2$ 且充分小的 $\epsilon$,存在唯一的经典解 $(\rho, w)$,其能量 $E_0(\tau)$ 和耗散 $D_0(\tau)$ 满足时间一致上界。进一步,若初始密度梯度 $\|\nabla \rho_0\|_{L^4}$ 充分小,则存在全局经典解,且满足指数衰减估计:$\sup_{\tau \geq 0} e^{c_0\tau}(\|\epsilon^{\alpha/2}w\|_{H^3}^2 + \|\rho - M\|_{H^3}^2) + \int_0^\infty e^{c_0\tau}(\|\epsilon^{\alpha/2-1}w\|_{H^3}^2 + \|\rho - M\|_{H^3}^2)d\tau \leq C_2$,以及 $L^\infty$ 和 $L^4$ 范数的衰减估计(公式(1.16))。
定理1.5(大摩擦极限)证明当 $\epsilon \to 0$ 时,原EP系统的解 $(\rho, u)$ 在适当意义下收敛到KS系统的解 $\sigma$。具体而言,$\rho - M$ 在 $L^\infty(0,T;H^3)$ 中 weak-* 收敛,在 $L^2(0,T;H^3)$ 中弱收敛,并在 $C(0,T;H^2_{\text{loc}})$ 中强收敛。特别重要的是,极限过程不产生任何奇点,且收敛解 $\sigma$ 满足KS系统并保持初始条件。
推论1.6表明在一维情形下,定理1.3(ii)和定理1.5的结论仍然成立,但正则性空间从 $H^3$ 降至 $H^2$,并且消除了 $\|\nabla \rho_0\|_{L^4}$ 的小性假设。这意味着在一维情况下,即使初始密度梯度不small,也能获得全局解。
3. 研究方法、关键技术和核心工具
论文采用直接奇点极限方法而非相对熵方法。核心创新在于引入中间系统(公式(1.9)),通过变量替换 $u = \epsilon v_\rho + \epsilon^\alpha w$ 将KS系统的特征显式分离出来,同时将系统奇异性与极限系统解耦,从而在保持相同正则性的前提下完成极限过程。
具体技术层面包含一系列一致估计:首先利用Keller-Segel映射 $v_\rho = -\nabla(-\Delta)^{-1}(\rho - M)$ 的椭圆正则性(公式(2.2)-(2.3))建立基本估计。L²估计通过将系统(1.9b)与 $w$ 做内积,结合积分技巧导出了能量泛函 $E_0(\tau)$ 和耗散泛函 $D_0(\tau)$ 满足微分不等式(公式(2.14)),关键在于控制非线性项的高阶耦合。H³估计则通过对空间导数逐次作用原始系统,利用Leibniz法则处理大量交叉项,结合椭圆估计和乘法代数性质完成闭合。局部时间存在性通过标准连续性参数方法证明,而全局性需要额外的 $\|\nabla \rho_0\|_{L^4}$ 小性假设来封闭迭代过程。最后,在验证先验假设(2.1)时,利用了最大原理和椭圆方程的正则性理论。
对于一维情况,作者还采用特征方法分析渐近行为,这在论文第4节单独处理。整个分析中最关键的洞察是:大摩擦通过 $\epsilon^\alpha$ 项提供耗散,但密度本身不直接受摩擦影响,耗散需通过电场间接传递,这使得估计不具备对 $\epsilon$ 的简单线性结构,从而产生了"初始层"现象——时间导数在 $\epsilon \to 0$ 时不一致有界(公式(3.2))。
4. 与之前工作的比较
与经典的Euler-Poisson系统研究相比,本文的工作在假设条件和结论上都有显著突破。早期工作如[31,32,34-36,42,44]利用Klein-Gordon效应仅对无旋扰动的平衡态$(M,0)$建立了小扰动全局解,需要同时要求速度和密度扰动都小。而[56]在三维外区域考虑了阻尼情形。本文则利用大摩擦机制,仅要求初始速度的$H^3$范数小且初始密度梯度的$L^4$范数小,允许$\|\rho_0 - M\|_{H^3}$不small,只要初始数据在远离真空的范围内。这是摩擦机制作为稳定化因素的重要体现。
就Keller-Segel系统而言,生产型KS系统众所周知会有限时间爆破,而消耗型在抛物-椭圆或抛物-抛物扩散模型下具有全局适定性。本文在双曲-椭圆消耗型框架下,证明了无真空条件下光滑全局解的存在性。特别地,一维结果对比[54]显示:在消耗型情况下,本文证明无奇点形成,而生产型情况下[54]展示了奇点形成。此外,[48]证明了一般双曲系统情况下即使消耗型也会有限时间爆破,说明双曲-椭圆耦合的关键作用。
方法论上,[30]使用相对熵方法要求极限系统解比原系统更正则,这在某些情形下难以验证。本文的直接极限方法保持了两者正则性相同,更清晰地揭示了无奇点形成的机制。然而,本文受限于非真空假设(公式(1.11)),因为真空出现时KS系统$H^s$($s \geq 1$)范数会随时间增长,这与框架不兼容。因此,真空情形被留作未来工作,这也与[48]的加权Sobolev空间框架形成呼应。
了解领域论文(摘要翻译)
1. 加性迹类噪声下随机Burgers方程噪声扰动的效应量化研究
Quantifying the effect of noise perturbation for the stochastic Burgers equation with additive trace-class noise
作者: Sonja Cox, Matas Urbonas
类别: math.PR, math.AP, math.NA
发布日期: 2026-03-19
arXiv ID: 2603.19071v1
链接: http://arxiv.org/abs/2603.19071v1
摘要翻译
中文标题: 加性迹类噪声下随机Burgers方程噪声扰动的效应量化研究
摘要翻译: 我们研究了驱动随机Burgers方程的噪声受到扰动时所产生的弱误差与强误差的上界。假设噪声为加性迹类噪声,且初始值具有足够高的正则性。更具体地,在Burgers方程中将驱动噪声的协方差算子 $Q_1 \in \mathcal{L}_1(L^2)$ 替换为另一协方差算子 $Q_2 \in \mathcal{L}_1(L^2)$ 时,所产生的弱误差阶为 $\mathcal{O}\big(\| (-A)^{-1} (Q_1-Q_2) \|_{\mathcal{L}_1(L^2)}\big)$,强误差阶为 $\mathcal{O}\big(\big\| (-A)^{-1/2}\big(Q_1^{1/2} -Q_2^{1/2}\big) \big\|_{\mathcal{L}_2(L^2)}\big)$。此处 $\|\cdot\|_{\mathcal{L}_1}$ 表示迹类范数,$\|\cdot\|_{\mathcal{L}_2}$ 表示希尔伯特-施密特范数,而 $A$ 代表Burgers方程主项所对应的一维狄利克雷拉普拉斯算子。特别地,我们的结果给出了用有限维噪声逼近迹类噪声时所产生的弱误差与强误差的上界;所得收敛阶体现了弱收敛速率通常应为强收敛速率两倍的一般性原理。
2. 与AKNS谱问题相关的$\bar\partial$问题的适定性
Well-posedness for the $\bar\partial$-problem relevant to the AKNS spectral problem
作者: Junyi Zhu, Huan Liu
类别: math.AP, math-ph
发布日期: 2026-03-19
arXiv ID: 2603.18930v1
链接: http://arxiv.org/abs/2603.18930v1
摘要翻译
中文标题: 与AKNS谱问题相关的$\bar\partial$问题的适定性
摘要翻译: 本文研究与AKNS谱问题相联系的Dbar问题的适定性。一般而言,带有归一化条件的相关Dbar方程等价于一个积分方程,其核中包含以物理变量$x$作为参数的指数项$\mathrm{e}^{\pm2ikx}$。我们通过定义一个新的积分算子$RT_{\mathbb{C}}(k;x)$,发展了一种分解技巧以控制该积分的收敛性。获得了该算子的小范数条件,从而证明Dbar问题存在唯一解。此外,我们将Dbar dressing方法推广至构造AKNS谱问题,并通过Dbar数据给出了势的显式构造。给出了先验估计,以证明从Dbar数据到AKNS势的映射是Lipschitz连续的。
3. 具有独立漂移的交叉扩散系统存在性理论:混合动力学
Existence Theory for a Cross-Diffusion System with Independent Drifts: Mixing Dynamics
作者: Alpár R. Mészáros, Guy Parker
类别: math.AP
发布日期: 2026-03-19
arXiv ID: 2603.18770v1
链接: http://arxiv.org/abs/2603.18770v1
摘要翻译
中文标题: 具有独立漂移的交叉扩散系统存在性理论:混合动力学
摘要翻译: 我们研究一类交叉扩散系统,其中每个物种的扩散仅通过总密度(以对数型或快扩散型压强律的形式)驱动。该模型定义在一维有界区间上,满足无通量边界条件,并允许存在不同物种间可异的势漂移项。我们无需假设解的总混合性,便建立了解的全局存在性。由此,我们完全解决了近期作者及Elbar–Santambrogio所研究的偏微分方程组,将初值范围推广至更广泛的一般类别(有限有界变差),且无需对其支撑集施加额外的结构假设。
4. 一维二次Klein-Gordon方程中孤子内模的辐射阻尼
Radiation damping of the soliton internal mode in 1D quadratic Klein-Gordon equation
作者: Piotr Bizoń, Tomasz Romańczukiewicz
类别: math-ph, math.AP
发布日期: 2026-03-19
arXiv ID: 2603.18605v1
链接: http://arxiv.org/abs/2603.18605v1
摘要翻译
中文标题: 一维二次Klein-Gordon方程中孤子内模的辐射阻尼
摘要翻译: 我们研究了一维二次Klein-Gordon方程中小幅度偶扰动孤子的长时间动力学行为。该孤子同时具备内模和不稳定模。在精细调节的初始数据构成的余维一流形上,不稳定性被抑制,内模通过向连续谱转移能量而缓慢衰减。我们证明这种衰减及相关非线性频移能够被一个三次共振近似精确刻画,其阻尼速率由类费米黄金规则系数决定。这为内模向色散辐射的不可逆能量转移提供了定量描述。
5. 论散度算子:自由空间与消失电荷
On divergence operators: Free space and vanishing charges
作者: Thierry De Pauw
类别: math.AP, math.FA
发布日期: 2026-03-19
arXiv ID: 2603.18441v1
链接: http://arxiv.org/abs/2603.18441v1
摘要翻译
中文标题: 论散度算子:自由空间与消失电荷
摘要翻译: 我们利用局部化拓扑方法,在临界情形 $v \in L^1(\Omega;\mathbb{R}^m)$ 或 $v \in C_0(\Omega;\mathbb{R}^m)$ 下,证明了散度方程 $\mathrm{div} (v) = F$ 的存在性与最优正则性结果,即刻画了所有使得存在解 $v$ 且其范数可由 $F$ 的相应范数控制的 $F$。我们假设区域 $\Omega$ 满足庞加莱不等式或延拓性质。基于一般理论,我们在每种情况下给出了容许 $F$ 的具体示例。
6. 球对称黑洞弱类光奇点附近两种球对称完美流体行为的对比
Contrasting behaviour of two spherically symmetric perfect fluids near a weak null singularity in a spherically symmetric black hole
作者: Raya V. Mancheva
类别: gr-qc, math.AP
发布日期: 2026-03-18
arXiv ID: 2603.18340v1
链接: http://arxiv.org/abs/2603.18340v1
摘要翻译
中文标题: 球对称黑洞弱类光奇点附近两种球对称完美流体行为的对比
摘要翻译: 本文对比了一类具有弱类光奇点的球对称时空中的两种球对称物质模型的行为。此类时空特别包含次 extremal Reissner-Nordström (RN) 黑洞在 Einstein-Maxwell-标量场系统下的球对称扰动,该系统的强宇宙监督猜想的 C² 形式已被 Luk-Oh (arXiv:1702.05715) 和 Dafermos (arXiv:1201.1797) 所证明。首先,我们考虑球对称尘埃落入弱类光奇点 (WNS) 的柯西问题,其中初始尘埃速度垂直于具有某些性质的平滑类空曲线。我们证明:在奇点之前或处,尘埃速度流不会发生任何壳层交叉,速度矢量保持类时,且当物质趋近奇点时尘埃能量密度保持有界。其次,我们考虑刚性完美流体落入 WNS 的特征初值问题。通过建立刚性流体速度与能量密度对满足齐次线性波动方程的标量场的等价关系,我们证明该能量密度在趋近弱类光奇点时趋于无穷。此外,我们表明刚性流体的向内分量在奇点处发散,而向外分量趋近于零。因此,速度矢量趋近于一个与奇点超面相切的向内类光矢量。
7. 复值mKdV方程的低正则性不变测度
Low-regularity invariant measure for the complex-valued mKdV
作者: Zachary Lee, Nataša Pavlović, Gigliola Staffilani, Nicola Visciglia
类别: math.AP
发布日期: 2026-03-18
arXiv ID: 2603.18310v1
链接: http://arxiv.org/abs/2603.18310v1
摘要翻译
中文标题: 复值mKdV方程的低正则性不变测度
摘要翻译: 本文考虑Chapouto引入的在一维环面上的双重整化复值修正KdV(mKdV)方程。我们的主要结果是构造一个支撑在低正则性空间的不变测度。这项工作补充了Kenig等人关于非重整化mKdV在高正则性空间构造不变测度的工作。由于测度支撑的低正则性,我们被迫在傅里叶-勒贝格空间中工作。考虑复值mKdV使得问题比之前考虑的实值情况更为复杂。
8. 超弹性与粘弹性框架下的非线性不可压缩剪切波模型及其在Love波中的应用
Nonlinear Incompressible Shear Wave Models in Hyperelasticity and Viscoelasticity Frameworks, with Applications to Love Waves
作者: Shawn Samuel Carl McAdam, Samuel Opoku Agyemang, Alexei Cheviakov
类别: nlin.SI, math-ph, math.AP, math.NA
发布日期: 2026-03-18
arXiv ID: 2603.18296v1
链接: http://arxiv.org/abs/2603.18296v1
摘要翻译
中文标题: 超弹性与粘弹性框架下的非线性不可压缩剪切波模型及其在Love波中的应用
摘要翻译: 本文提出描述不可压缩超弹性材料剪切位移的通用方程,该方程适用于任意形式的应变能密度函数,并应用于不同力学性能材料界面处传播的非线性Love型波。该模型适用于广泛的超-粘弹性材料类别。对于立方Yeoh模型,剪切波方程包含三阶与五阶微分多项式项,其粘弹性贡献体现为含材料位移混合导数$u_{xxt}$的色散项。对两层固体中传播的波开展了全(2+1)维数值模拟,并针对波源位置与层间力学性能进行分析。追踪了界面非线性Love波与自由上表面剪切波;结果表明,在完全非线性情形下,界面波与表面波的变波速普遍满足线性Love波存在条件$c_1 < \abs{v} < c_2$,且长时间后趋向于较大材料波速$c_1$或$c_2$。
9. 矩形区域上四速度平面Broadwell模型非定常初边值问题经典解的全局存在唯一性
Global-in-time existence and uniqueness of classical solutions to the unsteady initial-boundary value problem for the four-velocity planar Broadwell model in a rectangular domain
作者: Koudzo Togbévi Selom Sobah, Amah Séna D’Almeida
类别: math.AP
发布日期: 2026-03-18
arXiv ID: 2603.18269v1
链接: http://arxiv.org/abs/2603.18269v1
摘要翻译
中文标题: 矩形区域上四速度平面Broadwell模型非定常初边值问题经典解的全局存在唯一性
摘要翻译: 本文在矩形区域上,针对四速度平面Broadwell模型的非定常初边值问题,建立了经典解的全局存在唯一性结果。该结论在离散动理学理论框架下获得,适用于充分小的初始数据和边界数据。
不相关论文(基本信息)
1. 神经PDE求解器的严格误差认证:从经验残差到解保证
Rigorous Error Certification for Neural PDE Solvers: From Empirical Residuals to Solution Guarantees
作者: Amartya Mukherjee, Maxwell Fitzsimmons, David C. Del Rey Fernández, Jun Liu
类别: cs.LG, math.AP, math.FA
发布日期: 2026-03-19
arXiv ID: 2603.19165v1
链接: http://arxiv.org/abs/2603.19165v1
摘要: Uncertainty quantification for partial differential equations is traditionally grounded in discretization theory, where solution error is controlled via mesh/grid refinement. Physics-informed neural networks fundamentally depart from this paradigm: they approximate solutions by minimizing residual losses at collocation points, introducing new sources of error arising from optimization, sampling, representation, and overfitting. As a result, the generalization error in the solution space remains an open problem. Our main theoretical contribution establishes generalization bounds that connect residual control to solution-space error. We prove that when neural approximations lie in a compact subset of the solution space, vanishing residual error guarantees convergence to the true solution. We derive deterministic and probabilistic convergence results and provide certified generalization bounds translating residual, boundary, and initial errors into explicit solution error guarantees.
2. 关于与Ornstein-Uhlenbeck算子相关的Brunn-Minkowski型不等式的注记
Remarks on Brunn-Minkowski-type inequalities related to the Ornstein-Uhlenbeck operator
作者: Francisco Marín Sola, Francesco Salerno
类别: math.AP, math.MG
发布日期: 2026-03-19
arXiv ID: 2603.19164v1
链接: http://arxiv.org/abs/2603.19164v1
摘要: We investigate Brunn-Minkowski-type inequalities for the torsional rigidity $T_γ$ and the first eigenvalue $λ_γ$ associated with the Ornstein-Uhlenbeck operator. Counterexamples are provided showing that neither concavity nor convexity properties hold for $T_γ$ on general bounded convex sets. We also demonstrate that log-concavity and log-convexity properties fail in this setting. In the case of centrally symmetric sets, we answer a question raised by Cordero-Erausquin and Eskenazis by showing that $T_γ^{1/(n+2)}$ is neither convex nor concave. On the positive side, we prove that $T_γ^{1/3}$ is convex with respect to Minkowski addition when restricted to Euclidean balls centered at the origin. For $λ_γ$, we answer negatively a question posed by Colesanti, Francini, Livshyts, and Salani by showing that the inequality $λ_γ(Ω_t)^{-1/2} \geq (1-t)λ_γ(Ω_0)^{-1/2} + tλ_γ(Ω_1)^{-1/2}$ does not hold, even for centrally symmetric sets.
3. 混合测度与单调性下退化蒙日-安培方程的变分方法
A Variational Approach to Degenerate Monge–Ampère Equations with Mixed Measures and Monotonicity
作者: Nam Q. Le
类别: math.AP
发布日期: 2026-03-19
arXiv ID: 2603.19114v1
链接: http://arxiv.org/abs/2603.19114v1
摘要: We study the solvability and uniqueness for several degenerate Monge–Ampère equations including the Monge–Ampère eigenvalue problem in real Euclidean spaces that involve singular Borel measures. Our approach systematically analyzes the Monge–Ampère energy from the variational point of view and appropriately exploits monotonicity arguments. Our main tools consist of the mixed Monge–Ampère measure, Aleksandrov–Blocki–Jerison-type maximum principles, integration by parts, convex envelope, and comparison principles for subcritical equations. For the Monge–Ampère eigenvalue problem, we contrast the analysis within and without the energy class; even if it might not have solutions in the energy class, we show that the infimum of the Rayleigh quotient can be approximated from above by Monge–Ampère eigenvalues of the truncated measures, and by Rayleigh quotients of an inverse iterative scheme. We give examples showing that for very singular Borel measures, the Monge–Ampère eigenvalue problem has only solutions outside the energy class together with symmetry breaking and nonuniqueness.
4. 厄米特流形上Hessian算子和的方程的二阶估计
Second order estimates for equations with sums of Hessian operators on Hermitian manifolds
作者: Weisong Dong, Ruijia Zhang
类别: math.AP, math.DG
发布日期: 2026-03-19
arXiv ID: 2603.19045v1
链接: http://arxiv.org/abs/2603.19045v1
摘要: In this paper, we establish an a priori second-order estimate for admissible solutions satisfying a dynamic plurisubharmonic condition to equations involving sums of Hessian operators on compact Hermitian manifolds. The estimate is derived using a concavity inequality for complex sum-of-Hessian operators.
5. 正曲率黎曼流形上的苏达科夫分解
A Sudakov Decomposition in Riemannian Manifolds with Positive Curvature
作者: Zhengyao Huang
类别: math.AP, math.OC
发布日期: 2026-03-19
arXiv ID: 2603.18935v1
链接: http://arxiv.org/abs/2603.18935v1
摘要: In this paper, we study Monge’s problem on Riemannian manifolds $(M, g)$ with positive sectional curvature. Assuming that the source and target measures are absolutely continuous with respect to the Riemannian volume measure, we generalize a variational method from the Euclidean setting to establish the existence of a transport density and an explicit disintegration of measures along optimal rays. These results extend the approach of Bianchini-Caravenna to the Riemannian context.
6. 三维趋化逃避模型中的最优双线性控制
Optimal Bilinear control restricted to the three-dimensional chemo-repulsion model with potential production
作者: Francisco Guillen-Gonzalez, Exequiel Mallea-Zepeda, Maria A. Rodriguez-Bellido, Elder J. Villamizar-Roa
类别: math.AP, math.OC
发布日期: 2026-03-19
arXiv ID: 2603.18900v1
链接: http://arxiv.org/abs/2603.18900v1
摘要: In this paper we study the following three-dimensional parabolic-parabolic chemo-repulsion model with potential production, logistic reaction and bilinear control, defined in $Q=(0,T)\timesΩ$: \begin{equation*}\label{eq0} \left{ \begin{array}{rcl} \partial_tu-Δu&=&\nabla\cdot(u\nabla v)+r,u-μ, u^p,\ \partial_tv-Δv+v&=&u^p+f,v, 1_{Ω_c}, \end{array} \right. \end{equation*} where $1< p<+\infty$, $r,μ\geq 0$, and $f=f(t,x)$ is the control function acting on a subdomain $(0,T)\times Ω_c $, with $Ω_c\subseteqΩ$. This system is endowed with initial and non-flux boundary conditions. We prove the existence of global weak solutions of this controlled problem when $f\in L^{5/2}(0,T;L^{5/2}(Ω_c))$, analyzing the role of the diffusion and the logistic terms to get energy estimates. In particular, the logistic competition term $μ\, u^p$ is necessary only for $p>5/3$. Secondly, if $f\in L^{5/2}(0,T;L^{5/2+}(Ω_c))$, any weak solution $(u,v)$ satisfying the regularity criterion $u\in L^{5p/2}(Q)\cap L^{10/3}(Q)$ is in fact more regular, arriving in particular to $u,\nabla v\in L^5(Q)$ for $p\le 2$ and $u,\nabla v\in L^{5(p-1)}(Q)$ for $p> 2$ which is the critical regularity to solve a related optimal bilinear control problem. In fact, this setting let us to prove the existence of global optimal solutions, and the differentiability of the control-to-state mapping via the Implicit Function Theorem in Banach spaces. Then, we can identify the gradient of the (reduced) cost with respect to the control solving the adjoint problem by duality. In particular, we derive first-order necessary optimality conditions for local optimal solutions.
7. 带毛细边界的常平均曲率曲面与极小曲面的指标估计
Index Estimates for CMC and Minimal Surfaces with Capillary Boundary
作者: Luca Seemungal
类别: math.DG, math.AP
发布日期: 2026-03-19
arXiv ID: 2603.18783v1
链接: http://arxiv.org/abs/2603.18783v1
摘要: We prove that the index of a CMC surface with capillary boundary is bounded from above linearly by its genus, number of boundary components, and branching order, and also by some Willmore-type energy involving the area, mean curvature, contact angle, and ambient curvature. The main auxiliary theorem of more general interest is a comparison of the second variations of area and energy at a branched conformal map with boundary. In the appendix we derive the various second variation formulae for area, enclosed-volume, and wetting functionals away from critical points and for non-admissible variations, the purpose of which is to rather comprehensively fill a gap in the literature.
8. 基于物理基础的被动与主动用户频谱共享机制设计
Physics-grounded Mechanism Design for Spectrum Sharing between Passive and Active Users
作者: Jiguang Yu, Nicholas Brendle, Joel T. Johnson, David Starobinski
类别: math.AP, eess.SY
发布日期: 2026-03-19
arXiv ID: 2603.18776v1
链接: http://arxiv.org/abs/2603.18776v1
摘要: We propose a physics-grounded mechanism design for dynamic spectrum sharing that bridges the gap between radiometric retrieval constraints and economic incentives. We formulate the active and passive users coexistence problem as a Vickrey-Clarke-Groves (VCG) auctions mechanism, where the radiometer dynamically procures ``quiet’’ time-frequency tiles from active users based on the marginal reduction in retrieval error variance. This approach ensures allocative efficiency and dominant-strategy incentive compatibility (DSIC). To overcome the computational intractability of exact VCG on large grids, we derive an approximation algorithm by using the monotone submodularity induced by the radiometer equation. AMSR-2-based simulations show that the approach avoids high-cost tiles by aggregating low-cost spectrum across time and frequency. In an interference-trap case study, the proposed framework reduces procurement costs by about 60% over a fixed-band baseline while satisfying accuracy targets.
9. 麦克斯韦-布洛赫方程的单频渐近分析:混合态
On single-frequency asymptotics for the Maxwell-Bloch equations: mixed states
作者: . I. Komech, E. A. Kopylova
类别: math.AP, math-ph
发布日期: 2026-03-19
arXiv ID: 2603.18772v1
链接: http://arxiv.org/abs/2603.18772v1
摘要: We consider damped driven Maxwell-Bloch equations which are finite-dimensional approximation of the damped driven Maxwell-Schrödinger equations. The equations describe a single-mode Maxwell field coupled to a two-level molecule. Our main result is the construction of solutions with single-frequency asymptotics of the Maxwell field in the case of quasiperiodic pumping. The asymptotics hold for solutions with harmonic initial values which are stationary states of averaged equations in the interaction picture. We calculate all harmonic states and analyse their stability. The calculations rely on the Bloch-Feynman gyroscopic representation of von Neumann equation for the density matrix. The asymptotics follow by application of the averaging theory of the Bogolyubov type.
10. 病理蛋白通过脑网络的传播:以阿尔茨海默病为例
Spreading of pathological proteins through brain networks: a case study for Alzheimers disease
作者: G. Landi, A. Scaravelli, M. C. Tesi, C. Testa
类别: math.AP
发布日期: 2026-03-19
arXiv ID: 2603.18755v1
链接: http://arxiv.org/abs/2603.18755v1
摘要: Mathematical modeling offers a valuable approach to understanding Alzheimers disease (AD) given its complexity, unknown causes, and lack of effective treatments. Models, once validated, offer a powerful tool to test medical hypotheses that are otherwise difficult to verify directly. Our focus here is on elucidating the spread of misfolded tau protein, a critical hallmark of AD alongside Abeta protein, taking also into account the synergistic interaction between the two proteins. We consider distinct modelling choices, all employing network frameworks for protein evolution, differentiated by their network architecture and diffusion operators. By carefully comparing these models against clinical tau concentration data, gathered through advanced multimodal analysis techniques, we show that certain models replicate better the proteins dynamics. This investigation underscores a crucial insight: in modeling complex pathologies, the precision with which the mathematical framework is chosen is crucial, especially when validation against clinical data is considered decisive.
11. 带有间断非线性的诺伊曼问题
Neumann problem with a discontinuous nonlinearity
作者: Debajyoti Choudhuri, Dušan D. Repovš, Kamel Saoudi
类别: math.AP, math.FA
发布日期: 2026-03-19
arXiv ID: 2603.18732v1
链接: http://arxiv.org/abs/2603.18732v1
摘要: This study is devoted to proving the existence of weak solutions for a nonlinear elliptic problem with Neumann-type boundary data. The problem is driven by a discontinuous power nonlinearity and a nonsmooth prescribed data. Additionally, we aim to derive an estimate that proves the well-posedness of the problem. This estimate serves as an evidence for the uniqueness of the existing solution when the boundary term is ``smooth".
12. 长度泛函的齐次Sobolev梯度流
Homogeneous Sobolev gradient flow of the length functional
作者: Philip Schrader, Glen Wheeler, Valentina Wheeler
类别: math.DG, math.AP
发布日期: 2026-03-19
arXiv ID: 2603.18504v1
链接: http://arxiv.org/abs/2603.18504v1
摘要: We study the gradient flow of the length functional on the space of planar immersed closed curves, where the gradient is taken with respect to a family of homogeneous Sobolev $H^1$-type Riemannian metrics depending on parameters $λ>0$ and $a\in\mathbb{R}$. The gradient can be written explicitly in terms of arc-length convolution with the periodic Green’s function for the second-order operator associated with the $H^1$ metric, and then the gradient flow is a reparametrisation-invariant nonlocal ODE. Working in the optimal low-regularity setting $W^{1,1}(\mathbb{S},\mathbb{R}^2)$, we show that the gradient is locally Lipschitz to obtain local well-posedness via the Picard–Lindelöf theorem in Banach spaces. A time-reparametrisation reduces the analysis for general $a$ to the model case ${a=2}$, for which we obtain exponential decay of the length and global existence with uniform convergence in $W^{1,1}$ to a constant map. For $C^1$ immersed initial data we show that immersion is preserved for all time, and we further prove that if the initial curve bounds a convex set then convexity is also preserved by the flow.
13. 解决爆发问题:用于平均场神经元网络多次发放事件的时间膨胀数值框架
Resolving the Blow-Up: A Time-Dilated Numerical Framework for Multiple Firing Events in Mean-Field Neuronal Networks
作者: Xu’an Dou, Louis Tao, Zhe Xue, Zhennan Zhou
类别: math.NA, math.AP
发布日期: 2026-03-19
arXiv ID: 2603.18475v1
链接: http://arxiv.org/abs/2603.18475v1
摘要: In large-scale excitatory neuronal networks, rapid synchronization manifests as {multiple firing events (MFEs)}, mathematically characterized by a finite-time blow-up of the neuronal firing rate in the mean-field Fokker-Planck equation. Standard numerical methods struggle to resolve this singularity due to the divergent boundary flux and the instantaneous nature of the population voltage reset. In this work, we propose a robust {multiscale numerical framework based on time dilation}. By transforming the governing equation into a dilated timescale proportional to the firing activity, we desingularize the blow-up, effectively stretching the instantaneous synchronization event into a resolved mesoscopic process. This approach is shown to be physically consistent with the {microscopic cascade mechanism} underlying MFEs and the system’s inherent fragility. To implement this numerically, we develop a hybrid scheme that utilizes a {mesh-independent flux criterion} to switch between timescales and a semi-analytical ``moving Gaussian’’ method to accurately evolve the post-blowup Dirac mass. Numerical benchmarks demonstrate that our solver not only captures steady states with high accuracy but also efficiently reproduces periodic MFEs, matching Monte Carlo simulations without the severe time-step restrictions associated with particle cascades.
14. 由希亚雷-盖莫纳能量导出的非线性基尔霍夫-洛夫壳模型:建模与适定性
Nonlinear Kirchhoff-Love shell models derived from the Ciarlet-Geymonat energy: modelling and well-posedness
作者: Ionel-Dumitrel Ghiba, Trung Hieu Giang, Catalina Ureche
类别: math.AP, math-ph
发布日期: 2026-03-18
arXiv ID: 2603.18164v1
链接: http://arxiv.org/abs/2603.18164v1
摘要: Starting from a three-dimensional model based on the Ciarlet-Geymonat energy, we derive nonlinear shell models within the classical elasticity theory of compressible isotropic materials. The Neo-Hookean term involving the norm of the deformation gradient leads to an energy depending on the first, the second, and the third fundamental forms of the deformed midsurface. The coefficients appearing in the resulting shell models depend on the classical Lamé coefficients of the three-dimensional material, on the thickness of the shell, and on the mean and Gaussian curvatures of the reference configuration. This shows that the behavior of the shell is influenced not only by the elastic coefficients but also by the initial geometry of the three-dimensional thin body. The purely volumetric Ciarlet-Geymonat contribution of the three-dimensional energy leads to two-dimensional energies depending on the mean and Gaussian curvatures of both configurations, namely the undeformed and the deformed midsurfaces. Since a purely asymptotic derivation may lead to nonlinear terms for which the lower semicontinuity of the resulting functionals is not clear, we combine the asymptotic reduction through the thickness with Simpson’s quadrature rule applied to the purely volumetric energy terms, ensuring that the lower semicontinuity is inherited from the three-dimensional model. After deriving the model, we establish the well-posedness of the proposed shell energies. More precisely, we prove coercivity and lower semicontinuity property of the resulting functional and show the existence of minimizers in appropriate Sobolev spaces. A key ingredient in the proofs is a polyconvexity concept in the shell theory, together with some results concerning the weak convergence of terms involving the mean curvature of the deformed midsurface.