arXiv subjects

Tasuku Kubo

Publications and source records attributed to Tasuku Kubo.

2 recordsLinked to original sources

arXiv2026

Factorization of Time-Ordered Exponentials for Wiener Space Transformations

We develop an operator-algebraic framework for change-of-variables formulas on Wiener space, interpreting them as arising from hidden symmetries acting on observables. We show that general transformations can be represented by time-ordered exponentials generated by annihilation and creation operators, and that these admit an explicit factorization into a determinant, a multiplication operator, and a translation operator. Taking expectations recovers the classical formulas, including the Ramer--Kusuoka formula.

math.PR↗

arXiv2022

Monotonic normalized heat diffusion for regular bipartite graphs with four eigenvalues

Let $X=(V, E)$ be a finite regular graph and $H_t(u, v), \, u, v \in V$, the heat kernel on $X$. We prove that, if the graph $X$ is bipartite and has four distinct Laplacian eigenvalues, the ratio $H_t(u, v)/H_t(u, u), \, u, v \in V,$ is monotonically non-decreasing as a function of $t$. The key to the proof is the fact that such a graph is an incidence graph of a symmetric 2-design.

math.CO↗