arXiv subjects

Yu Aikawa

Publications and source records attributed to Yu Aikawa.

3 recordsLinked to original sources

arXiv2025

Bootstrapping Shape Invariance: Numerical Bootstrap as a Detector of Solvable Systems

Determining the solvability of a given quantum mechanical system is generally challenging. We discuss that the numerical bootstrap method can help us to solve this question in one-dimensional quantum mechanics. We show that the bootstrap method can derive exact energy eigenvalues in systems with shape invariance, which is a sufficient condition for solvability and which many solvable systems satisfy. The information of the annihilation operators is also obtained naturally, and thus the bootstrap method tells us why the system is solvable. We numerically demonstrate this explicitly for shape invariant potentials: harmonic oscillators, Morse potentials, Rosen-Morse potentials and hyperbolic Scarf potentials. Therefore, the numerical bootstrap method can determine the solvability of a given unknown system if it satisfies shape invariance.

hep-th↗

arXiv2021

Bootstrap Method in Harmonic Oscillator

Recently, an application of the numerical bootstrap method to quantum mechanics was proposed, and it successfully reproduces the eigenstates of various systems. However, it is unclear why this method works. In order to understand this question, we study the bootstrap method in harmonic oscillators. We find that the problem reduces to the Dirac's ladder operator problem and is exactly solvable analytically. Our result suggests that the bootstrap method may be regarded as a numerical version of the Dirac's approach and it may explain why it works in various systems.

hep-th↗

arXiv2021

Application of Bootstrap to $\theta$-term

Recently, novel numerical computation on quantum mechanics by using a bootstrap method was proposed by Han, Hartnoll, and Kruthoff. We consider whether this method works in systems with a $\theta$-term, where the standard Monte-Carlo computation may fail due to the sign problem. As a starting point, we study quantum mechanics of a charged particle on a circle in which a constant gauge potential is a counterpart of a $\theta$-term. We find that it is hard to determine physical quantities as functions of $\theta$ such as $E(\theta)$, except at $\theta=0$ and $\pi$. On the other hand, the correlations among observables for energy eigenstates are correctly reproduced for any $\theta$. Our results suggest that the bootstrap method may work not perfectly but sufficiently well, even if a $\theta$-term exists in the system.

hep-th↗