# Momenta spacing distributions in anharmonic oscillators and the higher order finite temperature Airy kernel

Abstract : We rigorously compute the integrable system for the limiting $(N\rightarrow\infty)$ distribution function of the extreme momentum of $N$ noninteracting fermions when confined to an anharmonic trap $V(q)=q^{2n}$ for $n\in\mathbb{Z}_{\geq 1}$ at positive temperature. More precisely, the edge momentum statistics in the harmonic trap $n=1$ are known to obey the weak asymmetric KPZ crossover law which is realized via the finite temperature Airy kernel determinant or equivalently via a Painlev\'e-II integro-differential transcendent, cf. \cite{LW,ACQ}. For general $n\geq 2$, a novel higher order finite temperature Airy kernel has recently emerged in physics literature \cite{DMS} and we show that the corresponding edge law in momentum space is now governed by a distinguished Painlev\'e-II integro-differential hierarchy. Our analysis is based on operator-valued Riemann-Hilbert techniques which produce a Lax pair for an operator-valued Painlev\'e-II ODE system that naturally encodes the aforementioned hierarchy. As byproduct, we establish a connection of the integro-differential Painlev\'e-II hierarchy to a novel integro-differential mKdV hierarchy.
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Preprints, Working Papers, ...
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https://hal.archives-ouvertes.fr/hal-03115038
Contributor : Sofia Tarricone Connect in order to contact the contributor
Submitted on : Tuesday, January 19, 2021 - 1:14:17 PM
Last modification on : Wednesday, October 20, 2021 - 3:19:02 AM

### Identifiers

• HAL Id : hal-03115038, version 1
• ARXIV : 2101.03557

### Citation

Thomas Bothner, Mattia Cafasso, Sofia Tarricone. Momenta spacing distributions in anharmonic oscillators and the higher order finite temperature Airy kernel. 2021. ⟨hal-03115038⟩

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