activity
20202026
most citedSemi-martingale driven variational principles

32 citations · 55 across the 16 of their papers we have counts for

collaborators

18 papers

physics.flu-dyn2026

Variational derivation of a moist thermal rotating shallow water model

Colin J. Cotter, Darryl D. Holm, Oliver D. Street

We introduce a new energy-conserving, moist shallow water model with thermal stratification and rotation. The model is derived from a variational principle, using a Lagrangian expr…

cond-mat.stat-mech2025

A comparative numerical study of stochastic Hamiltonian Camassa-Holm equations

Darryl D. Holm, Maneesh Kumar Singh, Oliver D. Street

We introduce a stochastic perturbation of the Camassa-Holm equation such that, unlike previous formulations, energy is conserved by the stochastic flow. We compare this to a comple…

nlin.PS2025

Compound Burgers-KdV Soliton Behaviour: Refraction, Reflection and Fusion

Darryl D. Holm, Ruiao Hu, Oliver D. Street +1

We consider a coupled PDE system between the Burgers equation and the KdV equation to model the interactions between `bore'-like structures and wave-like solitons in shallow water.…

math.PR2025

Symplectic techniques for stochastic differential equations on reductive Lie groups with applications to Langevin diffusions

Erwin Luesink, Oliver D. Street

We show how Langevin diffusions can be interpreted in the context of stochastic Hamiltonian systems with structure-preserving noise and dissipation on reductive Lie groups. Reducti…

physics.ao-ph2025

A thermal Green-Naghdi model with time dependent bathymetry and complete Coriolis force

Darryl D. Holm, Oliver D. Street

This paper extends the theoretical Euler-Poincaré framework for modelling ocean mixed layer dynamics. Through a symmetry-broken Lie group invariant variational principle, we derive…

physics.plasm-ph2025

Plasma dynamics in thin domains

Darryl D. Holm, Ruiao Hu, Oliver D. Street

In the present work, we study the geometric structures of the Rotating Shallow Water Magnetohydrodynamics (RSW-MHD) equations through a Lie group invariant Euler-Poincaré variation…

physics.flu-dyn2024

Collisions of Burgers Bores with Nonlinear Waves

Albert. Dombret, Darryl D. Holm, Ruiao Hu +2

This paper treats nonlinear wave current interactions in their simplest form, as an overtaking collision. In one spatial dimension, the paper investigates the collision interaction…

physics.plasm-ph2024★ 1 cited

Deterministic and Stochastic Geometric Mechanics for Hall MHD

Darryl D. Holm, Ruiao Hu, Oliver D. Street

We derive new models of stochastic Hall magnetohydrodynamics (MHD) by using a symmetry-reduced stochastic Euler-Poincaré variational principle. The new stochastic Hall MHD theory h…

physics.flu-dyn2024

Geometric theory of perturbation dynamics around non-equilibrium fluid flows

Darryl D. Holm, Ruiao Hu, Oliver D. Street

The present work investigates the evolution of linear perturbations of time-dependent ideal fluid flows with advected quantities, expressed in terms of the second order variations…

math-ph2023

Semimartingale driven mechanics and reduction by symmetry for stochastic and dissipative dynamical systems

Oliver D. Street, So Takao

The recent interest in structure preserving stochastic Lagrangian and Hamiltonian systems raises questions regarding how such models are to be understood and the principles through…

physics.flu-dyn2023

Geometric Mechanics of the Vertical Slice Model

Darryl D. Holm, Ruiao Hu, Oliver D. Street

The goals of the present work are to: (i) investigate the dynamics of oceanic frontogenesis by taking advantage of the geometric mechanics underlying the class of Vertical Slice Mo…

physics.flu-dyn2023

On the interactions between mean flows and inertial gravity waves in the WKB approximation

Darryl D. Holm, Ruiao Hu, Oliver D. Street

We derive a Wentzel-Kramers-Brillouin (WKB) closure of the generalised Lagrangian mean (GLM) theory by using a phase-averaged Hamilton variational principle for the Euler--Boussine…

math.AP2023★ 12 cited

Lagrangian reduction and wave mean flow interaction

Darryl D. Holm, Ruiao Hu, Oliver D. Street

How does one derive models of dynamical feedback effects in multiscale, multiphysics systems such as wave mean flow interaction (WMFI)? We shall address this question for hybrid dy…

physics.flu-dyn2022★ 3 cited

A structure preserving stochastic perturbation of classical water wave theory

Oliver D. Street

The inclusion of stochastic terms in equations of motion for fluid problems enables a statistical representation of processes which are left unresolved by numerical computation. He…

physics.ao-ph2022★ 7 cited

Coupling of waves to sea surface currents via horizontal density gradients

Darryl D. Holm, Ruiao Hu, Oliver D. Street

The mathematical models and numerical simulations reported here are motivated by satellite observations of horizontal gradients of sea surface temperature and salinity that are clo…

math.CA2021

On the analytical aspects of inertial particle motion

Dan Crisan, Oliver D. Street

In their seminal 1983 paper, M. Maxey and J. Riley introduced an equation for the motion of a sphere through a fluid. Since this equation features the Basset history integral, the…

physics.flu-dyn2020

Wave-current interaction on a free surface

Dan Crisan, Darryl D. Holm, Oliver D. Street

The classic evolution equations for potential flow on the free surface of a fluid flow are not closed because the pressure and the vertical velocity dynamics are not specified on t…

math-ph2020★ 32 cited

Semi-martingale driven variational principles

Oliver D. Street, Dan Crisan

Spearheaded by the recent efforts to derive stochastic geophysical fluid dynamics models, we present a generic framework for introducing stochasticity into variational principles t…