In this review, motivated by the recent interest in high-temperature materials, we review our recent progress in theories of lattice dynamics in and out of equilibrium. To investigate thermodynamic properties of anharmonic crystals, the self-consistent phonon theory was developed, mainly in the 1960s, for rare gas atoms and quantum crystals. We have extended this theory to investigate the properties of the equilibrium state of a crystal, including its unit cell shape and size, atomic positions and lattice dynamical properties. Using the equation-of-motion method combined with the fluctuation–dissipation theorem and the Donsker–Furutsu–Novikov (DFN) theorem, this approach was also extended to investigate the non-equilibrium case where there is heat flow across a junction or an interface. The formalism is a classical one and therefore valid at high temperatures.
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Unified analysis of algorithms for equilibrium, non-equilibrium, and hysteresis models of phase transition in permafrost
- PAR ID:
- 10556808
- Editor(s):
- Breit-Goodwin, Megan; Im, Mee-Seong; Jabbusch, Kelly; Lin, Kuei-Nuan
- Publisher / Repository:
- Association for Women in Mathematics Series, Advances in the Mathematical Sciences - AWM Research Symposium; Springer.
- Date Published:
- Page Range / eLocation ID:
- 2024
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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This paper studies Nash equilibrium problems that are given by polynomial functions. We formulate efficient polynomial optimization problems for computing Nash equilibria. The Moment-sum-of-squares relaxations are used to solve them. Under generic assumptions, the method can find a Nash equilibrium, if there is one. Moreover, it can find all Nash equilibria if there are finitely many ones of them. The method can also detect nonexistence if there is no Nash equilibrium. Funding: J. Nie was supported by the National Science Foundation [Grant DMS-2110780].more » « less
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