Mathematics of Computation最新文献

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Construction and analysis of a HDG solution for the total-flux formulation of the convected Helmholtz equation 共轭亥姆霍兹方程全通量公式的HDG解的构造和分析
2区 数学
Mathematics of Computation Pub Date : 2023-05-04 DOI: 10.1090/mcom/3850
Hélène Barucq, Nathan Rouxelin, Sébastien Tordeux
{"title":"Construction and analysis of a HDG solution for the total-flux formulation of the convected Helmholtz equation","authors":"Hélène Barucq, Nathan Rouxelin, Sébastien Tordeux","doi":"10.1090/mcom/3850","DOIUrl":"https://doi.org/10.1090/mcom/3850","url":null,"abstract":"We introduce a hybridizable discontinuous Galerkin (HDG) method for the convected Helmholtz equation based on the total flux formulation, in which the vector unknown represents both diffusive and convective phenomena. This HDG method is constricted with the same interpolation degree for all the unknowns and a physically informed value for the penalization parameter is computed. A detailed analysis including local and global well-posedness as well as a super-convergence result is carried out. We then provide numerical experiments to illustrate the theoretical results.","PeriodicalId":18456,"journal":{"name":"Mathematics of Computation","volume":"204 5 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-05-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136265188","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 1
Supercloseness of the local discontinuous Galerkin method for a singularly perturbed convection-diffusion problem 奇异摄动对流扩散问题局部不连续Galerkin方法的超逼近性
2区 数学
Mathematics of Computation Pub Date : 2023-05-04 DOI: 10.1090/mcom/3844
Yao Cheng, Shan Jiang, Martin Stynes
{"title":"Supercloseness of the local discontinuous Galerkin method for a singularly perturbed convection-diffusion problem","authors":"Yao Cheng, Shan Jiang, Martin Stynes","doi":"10.1090/mcom/3844","DOIUrl":"https://doi.org/10.1090/mcom/3844","url":null,"abstract":"A singularly perturbed convection-diffusion problem posed on the unit square in <inline-formula content-type=\"math/mathml\"> <mml:math xmlns:mml=\"http://www.w3.org/1998/Math/MathML\" alttext=\"double-struck upper R squared\"> <mml:semantics> <mml:msup> <mml:mrow class=\"MJX-TeXAtom-ORD\"> <mml:mi mathvariant=\"double-struck\">R</mml:mi> </mml:mrow> <mml:mn>2</mml:mn> </mml:msup> <mml:annotation encoding=\"application/x-tex\">mathbb {R}^2</mml:annotation> </mml:semantics> </mml:math> </inline-formula>, whose solution has exponential boundary layers, is solved numerically using the local discontinuous Galerkin (LDG) method with tensor-product piecewise polynomials of degree at most <inline-formula content-type=\"math/mathml\"> <mml:math xmlns:mml=\"http://www.w3.org/1998/Math/MathML\" alttext=\"k greater-than 0\"> <mml:semantics> <mml:mrow> <mml:mi>k</mml:mi> <mml:mo>></mml:mo> <mml:mn>0</mml:mn> </mml:mrow> <mml:annotation encoding=\"application/x-tex\">k>0</mml:annotation> </mml:semantics> </mml:math> </inline-formula> on three families of layer-adapted meshes: Shishkin-type, Bakhvalov-Shishkin-type and Bakhvalov-type. On Shishkin-type meshes this method is known to be no greater than <inline-formula content-type=\"math/mathml\"> <mml:math xmlns:mml=\"http://www.w3.org/1998/Math/MathML\" alttext=\"upper O left-parenthesis upper N Superscript minus left-parenthesis k plus 1 slash 2 right-parenthesis Baseline right-parenthesis\"> <mml:semantics> <mml:mrow> <mml:mi>O</mml:mi> <mml:mo stretchy=\"false\">(</mml:mo> <mml:msup> <mml:mi>N</mml:mi> <mml:mrow class=\"MJX-TeXAtom-ORD\"> <mml:mo>−<!-- − --></mml:mo> <mml:mo stretchy=\"false\">(</mml:mo> <mml:mi>k</mml:mi> <mml:mo>+</mml:mo> <mml:mn>1</mml:mn> <mml:mrow class=\"MJX-TeXAtom-ORD\"> <mml:mo>/</mml:mo> </mml:mrow> <mml:mn>2</mml:mn> <mml:mo stretchy=\"false\">)</mml:mo> </mml:mrow> </mml:msup> <mml:mo stretchy=\"false\">)</mml:mo> </mml:mrow> <mml:annotation encoding=\"application/x-tex\">O(N^{-(k+1/2)})</mml:annotation> </mml:semantics> </mml:math> </inline-formula> accurate in the energy norm induced by the bilinear form of the weak formulation, where <inline-formula content-type=\"math/mathml\"> <mml:math xmlns:mml=\"http://www.w3.org/1998/Math/MathML\" alttext=\"upper N\"> <mml:semantics> <mml:mi>N</mml:mi> <mml:annotation encoding=\"application/x-tex\">N</mml:annotation> </mml:semantics> </mml:math> </inline-formula> mesh intervals are used in each coordinate direction. (Note: all bounds in this abstract are uniform in the singular perturbation parameter and neglect logarithmic factors that will appear in our detailed analysis.) A delicate argument is used in this paper to establish <inline-formula content-type=\"math/mathml\"> <mml:math xmlns:mml=\"http://www.w3.org/1998/Math/MathML\" alttext=\"upper O left-parenthesis upper N Superscript minus left-parenthesis k plus 1 right-parenthesis Baseline right-parenthesis\"> <mml:semantics> <mml:mrow> <mml:mi>O</mml:mi> <mml:mo stretchy=\"false\">(</mml:mo> <mml:msup> <mml:mi>N</mml:mi> <mml:mro","PeriodicalId":18456,"journal":{"name":"Mathematics of Computation","volume":"5 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-05-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136231610","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 4
Divisibility conditions on the order of the reductions of algebraic numbers 代数数约化阶上的可整除性条件
2区 数学
Mathematics of Computation Pub Date : 2023-05-03 DOI: 10.1090/mcom/3848
Pietro Sgobba
{"title":"Divisibility conditions on the order of the reductions of algebraic numbers","authors":"Pietro Sgobba","doi":"10.1090/mcom/3848","DOIUrl":"https://doi.org/10.1090/mcom/3848","url":null,"abstract":"Let <inline-formula content-type=\"math/mathml\"> <mml:math xmlns:mml=\"http://www.w3.org/1998/Math/MathML\" alttext=\"upper K\"> <mml:semantics> <mml:mi>K</mml:mi> <mml:annotation encoding=\"application/x-tex\">K</mml:annotation> </mml:semantics> </mml:math> </inline-formula> be a number field, and let <inline-formula content-type=\"math/mathml\"> <mml:math xmlns:mml=\"http://www.w3.org/1998/Math/MathML\" alttext=\"upper G\"> <mml:semantics> <mml:mi>G</mml:mi> <mml:annotation encoding=\"application/x-tex\">G</mml:annotation> </mml:semantics> </mml:math> </inline-formula> be a finitely generated subgroup of <inline-formula content-type=\"math/mathml\"> <mml:math xmlns:mml=\"http://www.w3.org/1998/Math/MathML\" alttext=\"upper K Superscript times\"> <mml:semantics> <mml:msup> <mml:mi>K</mml:mi> <mml:mo>×<!-- × --></mml:mo> </mml:msup> <mml:annotation encoding=\"application/x-tex\">K^times</mml:annotation> </mml:semantics> </mml:math> </inline-formula>. Without relying on the Generalized Riemann Hypothesis we prove an asymptotic formula for the number of primes <inline-formula content-type=\"math/mathml\"> <mml:math xmlns:mml=\"http://www.w3.org/1998/Math/MathML\" alttext=\"German p\"> <mml:semantics> <mml:mrow class=\"MJX-TeXAtom-ORD\"> <mml:mi mathvariant=\"fraktur\">p</mml:mi> </mml:mrow> <mml:annotation encoding=\"application/x-tex\">mathfrak p</mml:annotation> </mml:semantics> </mml:math> </inline-formula> of <inline-formula content-type=\"math/mathml\"> <mml:math xmlns:mml=\"http://www.w3.org/1998/Math/MathML\" alttext=\"upper K\"> <mml:semantics> <mml:mi>K</mml:mi> <mml:annotation encoding=\"application/x-tex\">K</mml:annotation> </mml:semantics> </mml:math> </inline-formula> such that the order of <inline-formula content-type=\"math/mathml\"> <mml:math xmlns:mml=\"http://www.w3.org/1998/Math/MathML\" alttext=\"left-parenthesis upper G mod German p right-parenthesis\"> <mml:semantics> <mml:mrow> <mml:mo stretchy=\"false\">(</mml:mo> <mml:mi>G</mml:mi> <mml:mo lspace=\"thickmathspace\" rspace=\"thickmathspace\">mod</mml:mo> <mml:mrow class=\"MJX-TeXAtom-ORD\"> <mml:mi mathvariant=\"fraktur\">p</mml:mi> </mml:mrow> <mml:mo stretchy=\"false\">)</mml:mo> </mml:mrow> <mml:annotation encoding=\"application/x-tex\">(Gbmod mathfrak p)</mml:annotation> </mml:semantics> </mml:math> </inline-formula> is divisible by a fixed integer. We also provide a rational expression for the natural density of this set. Furthermore, we study the primes <inline-formula content-type=\"math/mathml\"> <mml:math xmlns:mml=\"http://www.w3.org/1998/Math/MathML\" alttext=\"German p\"> <mml:semantics> <mml:mrow class=\"MJX-TeXAtom-ORD\"> <mml:mi mathvariant=\"fraktur\">p</mml:mi> </mml:mrow> <mml:annotation encoding=\"application/x-tex\">mathfrak p</mml:annotation> </mml:semantics> </mml:math> </inline-formula> for which the order is <inline-formula content-type=\"math/mathml\"> <mml:math xmlns:mml=\"http://www.w3.org/1998/Math/MathML\" alttext=\"k\"> <mml:semantics> <mml:mi>k</mml:mi> <mml:annotation encoding=\"application/x-tex\">k</mml:annotation> </mml:","PeriodicalId":18456,"journal":{"name":"Mathematics of Computation","volume":"235 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-05-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134922467","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Splitting integrators for stochastic Lie–Poisson systems 随机Lie-Poisson系统的分裂积分器
2区 数学
Mathematics of Computation Pub Date : 2023-04-27 DOI: 10.1090/mcom/3829
Charles-Edouard Bréhier, David Cohen, Tobias Jahnke
{"title":"Splitting integrators for stochastic Lie–Poisson systems","authors":"Charles-Edouard Bréhier, David Cohen, Tobias Jahnke","doi":"10.1090/mcom/3829","DOIUrl":"https://doi.org/10.1090/mcom/3829","url":null,"abstract":"We study stochastic Poisson integrators for a class of stochastic Poisson systems driven by Stratonovich noise. Such geometric integrators preserve Casimir functions and the Poisson map property. For this purpose, we propose explicit stochastic Poisson integrators based on a splitting strategy, and analyse their qualitative and quantitative properties: preservation of Casimir functions, existence of almost sure or moment bounds, asymptotic preserving property, and strong and weak rates of convergence. The construction of the schemes and the theoretical results are illustrated through extensive numerical experiments for three examples of stochastic Lie–Poisson systems, namely: stochastically perturbed Maxwell–Bloch, rigid body and sine–Euler equations.","PeriodicalId":18456,"journal":{"name":"Mathematics of Computation","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-04-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136086440","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 1
Explicit bounds for products of primes in AP AP中素数乘积的显界
2区 数学
Mathematics of Computation Pub Date : 2023-04-21 DOI: 10.1090/mcom/3853
Ramachandran Balasubramanian, Olivier Ramaré, Priyamvad Srivastav
{"title":"Explicit bounds for products of primes in AP","authors":"Ramachandran Balasubramanian, Olivier Ramaré, Priyamvad Srivastav","doi":"10.1090/mcom/3853","DOIUrl":"https://doi.org/10.1090/mcom/3853","url":null,"abstract":"For all <inline-formula content-type=\"math/mathml\"> <mml:math xmlns:mml=\"http://www.w3.org/1998/Math/MathML\" alttext=\"q greater-than-or-equal-to 2\"> <mml:semantics> <mml:mrow> <mml:mi>q</mml:mi> <mml:mo>≥<!-- ≥ --></mml:mo> <mml:mn>2</mml:mn> </mml:mrow> <mml:annotation encoding=\"application/x-tex\">qge 2</mml:annotation> </mml:semantics> </mml:math> </inline-formula> and for all invertible residue classes <inline-formula content-type=\"math/mathml\"> <mml:math xmlns:mml=\"http://www.w3.org/1998/Math/MathML\" alttext=\"a\"> <mml:semantics> <mml:mi>a</mml:mi> <mml:annotation encoding=\"application/x-tex\">a</mml:annotation> </mml:semantics> </mml:math> </inline-formula> modulo <inline-formula content-type=\"math/mathml\"> <mml:math xmlns:mml=\"http://www.w3.org/1998/Math/MathML\" alttext=\"q\"> <mml:semantics> <mml:mi>q</mml:mi> <mml:annotation encoding=\"application/x-tex\">q</mml:annotation> </mml:semantics> </mml:math> </inline-formula>, there exists a natural number that is congruent to <inline-formula content-type=\"math/mathml\"> <mml:math xmlns:mml=\"http://www.w3.org/1998/Math/MathML\" alttext=\"a\"> <mml:semantics> <mml:mi>a</mml:mi> <mml:annotation encoding=\"application/x-tex\">a</mml:annotation> </mml:semantics> </mml:math> </inline-formula> modulo <inline-formula content-type=\"math/mathml\"> <mml:math xmlns:mml=\"http://www.w3.org/1998/Math/MathML\" alttext=\"q\"> <mml:semantics> <mml:mi>q</mml:mi> <mml:annotation encoding=\"application/x-tex\">q</mml:annotation> </mml:semantics> </mml:math> </inline-formula> and that is the product of exactly three primes, all of which are below <inline-formula content-type=\"math/mathml\"> <mml:math xmlns:mml=\"http://www.w3.org/1998/Math/MathML\" alttext=\"left-parenthesis 10 Superscript 15 Baseline q right-parenthesis Superscript 5 slash 2\"> <mml:semantics> <mml:mrow> <mml:mo stretchy=\"false\">(</mml:mo> <mml:msup> <mml:mn>10</mml:mn> <mml:mrow class=\"MJX-TeXAtom-ORD\"> <mml:mn>15</mml:mn> </mml:mrow> </mml:msup> <mml:mi>q</mml:mi> <mml:msup> <mml:mo stretchy=\"false\">)</mml:mo> <mml:mrow class=\"MJX-TeXAtom-ORD\"> <mml:mn>5</mml:mn> <mml:mrow class=\"MJX-TeXAtom-ORD\"> <mml:mo>/</mml:mo> </mml:mrow> <mml:mn>2</mml:mn> </mml:mrow> </mml:msup> </mml:mrow> <mml:annotation encoding=\"application/x-tex\">(10^{15}q)^{5/2}</mml:annotation> </mml:semantics> </mml:math> </inline-formula>.","PeriodicalId":18456,"journal":{"name":"Mathematics of Computation","volume":"45 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-04-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135463822","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Robust a posteriori estimates for the stochastic Cahn-Hilliard equation 随机Cahn-Hilliard方程的稳健后验估计
2区 数学
Mathematics of Computation Pub Date : 2023-04-19 DOI: 10.1090/mcom/3836
L’ubomír Baňas, Christian Vieth
{"title":"Robust a posteriori estimates for the stochastic Cahn-Hilliard equation","authors":"L’ubomír Baňas, Christian Vieth","doi":"10.1090/mcom/3836","DOIUrl":"https://doi.org/10.1090/mcom/3836","url":null,"abstract":"We derive a posteriori error estimates for a fully discrete finite element approximation of the stochastic Cahn-Hilliard equation. The a posteriori bound is obtained by a splitting of the equation into a linear stochastic partial differential equation and a nonlinear random partial differential equation. The resulting estimate is robust with respect to the interfacial width parameter and is computable since it involves the discrete principal eigenvalue of a linearized (stochastic) Cahn-Hilliard operator. Furthermore, the estimate is robust with respect to topological changes as well as the intensity of the stochastic noise. We provide numerical simulations to demonstrate the practicability of the proposed adaptive algorithm.","PeriodicalId":18456,"journal":{"name":"Mathematics of Computation","volume":"104 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-04-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135708611","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Jacobi-type algorithms for homogeneous polynomial optimization on Stiefel manifolds with applications to tensor approximations Stiefel流形上齐次多项式优化的jacobi型算法及其在张量逼近中的应用
2区 数学
Mathematics of Computation Pub Date : 2023-04-05 DOI: 10.1090/mcom/3834
Zhou Sheng, Jianze Li, Qin Ni
{"title":"Jacobi-type algorithms for homogeneous polynomial optimization on Stiefel manifolds with applications to tensor approximations","authors":"Zhou Sheng, Jianze Li, Qin Ni","doi":"10.1090/mcom/3834","DOIUrl":"https://doi.org/10.1090/mcom/3834","url":null,"abstract":"This paper mainly studies the gradient-based Jacobi-type algorithms to maximize two classes of homogeneous polynomials with orthogonality constraints, and establish their convergence properties. For the first class of homogeneous polynomials subject to a constraint on a Stiefel manifold, we reformulate it as an optimization problem on a unitary group, which makes it possible to apply the gradient-based Jacobi-type (Jacobi-G) algorithm. Then, if the subproblem can always be represented as a quadratic form, we establish the global convergence of Jacobi-G under any one of three conditions. The convergence result for the first condition is an easy extension of the result by Usevich, Li, and Comon [SIAM J. Optim. 30 (2020), pp. 2998–3028], while other two conditions are new ones. This algorithm and the convergence properties apply to the well-known joint approximate symmetric tensor diagonalization. For the second class of homogeneous polynomials subject to constraints on the product of Stiefel manifolds, we reformulate it as an optimization problem on the product of unitary groups, and then develop a new gradient-based multiblock Jacobi-type (Jacobi-MG) algorithm to solve it. We establish the global convergence of Jacobi-MG under any one of the above three conditions, if the subproblem can always be represented as a quadratic form. This algorithm and the convergence properties are suitable to the well-known joint approximate tensor diagonalization. As the proximal variants of Jacobi-G and Jacobi-MG, we also propose the Jacobi-GP and Jacobi-MGP algorithms, and establish their global convergence without any further condition. Some numerical results are provided indicating the efficiency of the proposed algorithms.","PeriodicalId":18456,"journal":{"name":"Mathematics of Computation","volume":"122 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-04-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135956560","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Thermodynamically consistent and positivity-preserving discretization of the thin-film equation with thermal noise 热噪声下薄膜方程的热力学一致性和保正离散化
2区 数学
Mathematics of Computation Pub Date : 2023-04-04 DOI: 10.1090/mcom/3830
Benjamin Gess, Rishabh S. Gvalani, Florian Kunick, Felix Otto
{"title":"Thermodynamically consistent and positivity-preserving discretization of the thin-film equation with thermal noise","authors":"Benjamin Gess, Rishabh S. Gvalani, Florian Kunick, Felix Otto","doi":"10.1090/mcom/3830","DOIUrl":"https://doi.org/10.1090/mcom/3830","url":null,"abstract":"In micro-fluidics, both capillarity and thermal fluctuations play an important role. On the level of the lubrication approximation, this leads to a quasi-linear fourth-order parabolic equation for the film height &lt;inline-formula content-type=\"math/mathml\"&gt; &lt;mml:math xmlns:mml=\"http://www.w3.org/1998/Math/MathML\" alttext=\"h\"&gt; &lt;mml:semantics&gt; &lt;mml:mi&gt;h&lt;/mml:mi&gt; &lt;mml:annotation encoding=\"application/x-tex\"&gt;h&lt;/mml:annotation&gt; &lt;/mml:semantics&gt; &lt;/mml:math&gt; &lt;/inline-formula&gt; driven by space-time white noise. The (formal) gradient flow structure of its deterministic counterpart, the so-called thin-film equation, which encodes the balance between driving capillary and limiting viscous forces, provides the guidance for the thermodynamically consistent introduction of fluctuations. We follow this route on the level of a spatial discretization of the gradient flow structure, i.e., on the level of a discretization of energy functional and dissipative metric tensor. Starting from an energetically conformal finite-element (FE) discretization, we point out that the numerical mobility function introduced by Grün and Rumpf can be interpreted as a discretization of the metric tensor in the sense of a mixed FE method with lumping. While this discretization was devised in order to preserve the so-called entropy estimate, we use this to show that the resulting high-dimensional stochastic differential equation (SDE) preserves pathwise and pointwise strict positivity, at least in case of the physically relevant mobility function arising from the no-slip boundary condition. As a consequence, and as opposed to previous discretizations of the thin-film equation with thermal noise, the above discretization is not in need of an artificial condition at the boundary of the configuration space orthant &lt;inline-formula content-type=\"math/mathml\"&gt; &lt;mml:math xmlns:mml=\"http://www.w3.org/1998/Math/MathML\" alttext=\"left-brace h greater-than 0 right-brace\"&gt; &lt;mml:semantics&gt; &lt;mml:mrow&gt; &lt;mml:mo fence=\"false\" stretchy=\"false\"&gt;{&lt;/mml:mo&gt; &lt;mml:mi&gt;h&lt;/mml:mi&gt; &lt;mml:mo&gt;&gt;&lt;/mml:mo&gt; &lt;mml:mn&gt;0&lt;/mml:mn&gt; &lt;mml:mo fence=\"false\" stretchy=\"false\"&gt;}&lt;/mml:mo&gt; &lt;/mml:mrow&gt; &lt;mml:annotation encoding=\"application/x-tex\"&gt;{h&gt;0}&lt;/mml:annotation&gt; &lt;/mml:semantics&gt; &lt;/mml:math&gt; &lt;/inline-formula&gt; (which, admittedly, could also be avoided by modelling a disjoining pressure). Thus, this discretization gives rise to a consistent invariant measure, namely a discretization of the Brownian excursion (up to the volume constraint), and thus features an entropic repulsion. The price to pay over more direct discretizations is that when writing the SDE in Itô’s form, which is the basis for the Euler-Mayurama time discretization, a correction term appears. We perform various numerical experiments to compare the behavior and performance of our discretization to that of a particular finite difference discretization of the equation. Among other things, we study numerically the invariance and entropic repulsion of the invariant ","PeriodicalId":18456,"journal":{"name":"Mathematics of Computation","volume":"68 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-04-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136088151","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Explicit and efficient error estimation for convex minimization problems 凸极小化问题的显式有效误差估计
2区 数学
Mathematics of Computation Pub Date : 2023-03-22 DOI: 10.1090/mcom/3821
Sören Bartels, Alex Kaltenbach
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引用次数: 1
Pointwise error estimates and local superconvergence of Jacobi expansions Jacobi展开的点态误差估计和局部超收敛性
2区 数学
Mathematics of Computation Pub Date : 2023-03-21 DOI: 10.1090/mcom/3835
Shuhuang Xiang, Desong Kong, Guidong Liu, Li-Lian Wang
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引用次数: 0
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