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arXiv 2402.13626math.AP
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用于相变的高阶奇异扰动模型

Higher-order singular perturbation models for phase transitions

Giuseppe Cosma Brusca, Davide Donati, Margherita Solci

AI总结:

本文研究双阱能量受 k 阶导数奇异扰动的相变模型,通过 Γ-收敛、有限区间最优剖面逼近及能量估计,建立含适当界面能密度的锐界面极限。

摘要:

相变的变分模型考虑了由梯度项奇异扰动的双阱能量,例如 Cahn–Hilliard 自由能。通过 Γ-收敛推导此类能量的锐界面极限,是 Modica 和 Mortola 的经典结果。我们考虑双阱能量受到 k 阶导数的奇异扰动,并证明在适当的界面能量密度下,仍能像 k=1 的情形那样描述该极限;这与 k=1 的情形以及此前由 Fonseca 和 Mantegazza 分析的 k=2 情形相符。主要问题是在实轴上推导一个描述界面能量密度的最优剖面问题,该问题必须通过有限区间上的极小化问题加以便利地逼近,并在端点处对直至 k−1 阶的导数施加齐次条件。为此,必须借助插值不等式和能量估计,仔细研究那些能量等度有界的函数序列“接近势阱”且具有“小导数”的集合。

英文摘要:

Variational models of phase transitions take into account double-well energies singularly perturbed by gradient terms, such as the Cahn-Hilliard free energy. The derivation by $Γ$-convergence of a sharp-interface limit for such energy is a classical result by Modica and Mortola. We consider a singular perturbation of a double-well energy by derivatives of order $k$, and show that we still can describe the limit as in the case $k=1$ with a suitable interfacial energy density, in accord with the case $k=1$ and with the case $k=2$ previously analyzed by Fonseca and Mantegazza. The main isssue is the derivation of an optimal-profile problem on the real line describing the interfacial energy density, which must be conveniently approximated by minimum problems on finite intervals with homogeneous condition on the derivatives at the endpoints up to order $k-1$. To that end a careful study must be carried on of sets where sequences of functions with equibounded energy are ``close to the wells'' and have ``small derivatives'', in terms of interpolation inequalities and energy estimates.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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