papers

Publications (6)

math.AP2022

A Hele-Shaw Limit With A Variable Upper Bound and Drift

Raymond Chu

We investigate a generalized Hele-Shaw equation with a source and drift terms where the density is constrained by an upper-bound density constraint that varies in space and time. B…

math.AP2025

The supercooled Stefan problem: fractal freezing and the fine structure of maximal solutions

Raymond Chu, Inwon Kim, Sebastian Munoz

We study the supercooled Stefan problem in arbitrary dimensions. First, we study general solutions and their irregularities, showing generic fractal freezing and nucleation, based…

cs.LG2026

Rate-Optimal Noise Annealing in Semi-Dual Neural Optimal Transport: Tangential Identifiability, Off-Manifold Ambiguity, and Guaranteed Recovery

Raymond Chu, Jaewoong Choi, Dohyun Kwon

Semi-dual neural optimal transport learns a transport map via a max-min objective, yet training can converge to incorrect or degenerate maps. We fully characterize these spurious s…

math.AP2025

Guaranteeing Higher Order Convergence Rates for Accelerated Wasserstein Gradient Flow Schemes

Raymond Chu, Matt Jacobs

In this paper, we study higher-order-accurate-in-time minimizing movements schemes for Wasserstein gradient flows. We introduce a novel accelerated second-order scheme, leveraging…

physics.flu-dyn2021

Fast Asymptotic-Numerical Method For Coarse Mesh Particle Simulation In Channels Of Arbitrary Cross Section

Samuel Christensen, Raymond Chu, Christopher R Anderson +1

Particles traveling through inertial microfluidic devices migrate to focusing streamlines. We present a numerical method that calculates migration velocities of particles in inerti…

math.AP2024

The Nonlocal Stefan Problem via a Martingale Transport

Raymond Chu, Inwon Kim, Young-Heon Kim +1

We study the nonlocal Stefan problem, where the phase transition is described by a nonlocal diffusion as well as the change of enthalpy functions. By using a stochastic optimizatio…