English
Related papers

Related papers: Quartic Gradient Flow

200 papers

Quaternion-valued signal processing has received increasing attention recently. One key operation involved in derivation of all kinds of adaptive algorithms is the gradient operator. Although there have been some derivations of this…

Optimization and Control · Mathematics 2014-06-24 Mengdi Jiang , Wei Liu , Yi Li

In this paper, we analyze gradient-free methods with one-point feedback for stochastic saddle point problems $\min_{x}\max_{y} \varphi(x, y)$. For non-smooth and smooth cases, we present analysis in a general geometric setup with arbitrary…

Optimization and Control · Mathematics 2022-09-12 Aleksandr Beznosikov , Vasilii Novitskii , Alexander Gasnikov

The gradient-flow formalism proves to be a useful tool in lattice calculations of quantum chromodynamics. For example, it can be used as a scheme to renormalize composite operators by inverting the short-flow-time expansion of the…

High Energy Physics - Lattice · Physics 2024-11-05 Janosch Borgulat , Robert V. Harlander , Jonas T. Kohnen , Fabian Lange

We present a formalism for semiclassical time evolution in quantum mechanics, building on a century of work. We identify complex saddle points in real time, real saddle points in complex time, and complex saddle points in complex time that…

High Energy Physics - Theory · Physics 2026-03-09 Oliver Janssen , Joel Karlsson , Flavio Riccardi , Mattia Varrone

This is an expository paper on the theory of gradient flows, and in particular of those PDEs which can be interpreted as gradient flows for the Wasserstein metric on the space of probability measures (a distance induced by optimal…

Analysis of PDEs · Mathematics 2016-09-14 Filippo Santambrogio

Let $M$ be either $n$-sphere $\mathbb{S}^{n}$ or a connected sum of finitely many copies of $\mathbb{S}^{n-1}\times \mathbb{S}^{1}$, $n\geq4$. A flow $f^t$ on $M$ is called gradient-like whenever its non-wandering set consists of finitely…

Dynamical Systems · Mathematics 2021-11-09 Vyacheslav Grines , Elena Gurevich , Sergiy Maksymenko

Gradient flow in a potential energy (or Euclidean action) landscape provides a natural set of paths connecting different saddle points. We apply this method to General Relativity, where gradient flow is Ricci flow, and focus on the example…

High Energy Physics - Theory · Physics 2009-11-11 Matthew Headrick , Toby Wiseman

We propose a supersymmetric gradient flow in ${\cal N}=1$ SQCD in four dimensions. The flow equation is derived in the superfield formalism and is also given for component fields of the Wess-Zumino gauge in a gauge covariant manner. We find…

High Energy Physics - Lattice · Physics 2020-01-01 Daisuke Kadoh , Naoya Ukita

In the paper, we generalize the approach Gasnikov et. al, 2017, which allows to solve (stochastic) convex optimization problems with an inexact gradient-free oracle, to the convex-concave saddle-point problem. The proposed approach works,…

Optimization and Control · Mathematics 2022-09-13 Aleksandr Beznosikov , Abdurakhmon Sadiev , Alexander Gasnikov

A method for locating first order saddle points on the energy surface of a magnetic system is described and several applications presented where the mechanism of various magnetic transitions is identified. The starting point for the…

Computational Physics · Physics 2025-01-17 Hendrik Schrautzer , Moritz Sallermann , Pavel F. Bessarab , Hannes Jónsson

The existence of stationary points for the dynamical system of ABC-flow is considered. The ABC-flow, a three-parameter velocity field that provides a simple stationary solution of Euler's equations in three dimensions for incompressible,…

General Physics · Physics 2016-01-11 Sergey V. Ershkov

We introduce a class of unconditionally energy stable, high order accurate schemes for gradient flows in a very general setting. The new schemes are a high order analogue of the minimizing movements approach for generating a time discrete…

Numerical Analysis · Mathematics 2020-02-11 Alexander Zaitzeff , Selim Esedoglu , Krishna Garikipati

Saddle points provide a hierarchical view of the energy landscape, revealing transition pathways and interconnected basins of attraction, and offering insight into the global structure, metastability, and possible collective mechanisms of…

Numerical Analysis · Mathematics 2025-10-17 Baoming Shi , Lei Zhang , Qiang Du

A classical description of the dynamics of a dissipative charged-particle fluid in a quadrupole-like device is developed. It is shown that the set of the classical fluid equations contains the same information as a complex function…

Quantum Physics · Physics 2009-11-07 S. De Nicola , R. Fedele , V. I. Man'ko

Escaping saddle points is a central research topic in nonconvex optimization. In this paper, we propose a simple gradient-based algorithm such that for a smooth function $f\colon\mathbb{R}^n\to\mathbb{R}$, it outputs an…

Optimization and Control · Mathematics 2021-11-30 Chenyi Zhang , Tongyang Li

This work proposes a quaternion-based sliding variable that describes exponentially convergent error dynamics for any forward complete desired attitude trajectory. The proposed sliding variable directly operates on the non-Euclidean space…

Robotics · Computer Science 2020-11-10 Brett T. Lopez , Jean-Jacques E. Slotine

The gradient-flow dynamics of an arbitrary geometric quantity is derived using a generalization of Darcy's Law. We consider flows in both Lagrangian and Eulerian formulations. The Lagrangian formulation includes a dissipative modification…

Adaptation and Self-Organizing Systems · Physics 2008-04-28 Darryl D. Holm , Vakhtang Putkaradze , Cesare Tronci

Lattice calculations of hadronic observables are aggravated by short-distance fluctuations. The gradient flow, which can be viewed as a particular realisation of the coarse-graining step of momentum space RG transformations, proves a…

High Energy Physics - Lattice · Physics 2021-12-14 K. U. Can , R. Horsley , Y. Nakamura , H. Perlt , P. E. L. Rakow , G. Schierholz , H. Stüben , R. D. Young , J. M. Zanotti

We introduce a new stochastic algorithm to locate the index-1 saddle points of a function $V:\mathbb R^d \to \mathbb R$, with $d$ possibly large. This algorithm can be seen as an equivalent of the stochastic gradient descent which is a…

Numerical Analysis · Mathematics 2023-08-24 Tony Lelièvre , Panos Parpas

A machine learning method to predict steady external fluid flows using elliptic input features is introduced. Using data from as few as one high-fidelity simulation, the proposed method produces models generalizable under changes to…