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Stochastic Gradient Descent (SGD) is widely used in machine learning research. Previous convergence analyses of SGD under the vanishing step-size setting typically require Robbins-Monro conditions. However, in practice, a wider variety of…

Machine Learning · Computer Science 2025-04-18 Ruinan Jin , Difei Cheng , Hong Qiao , Xin Shi , Shaodong Liu , Bo Zhang

Relativistic simulations in 3+1 dimensions typically monitor the Hamiltonian and momentum constraints during evolution, with significant violations of these constraints indicating the presence of instabilities. In this paper we rewrite the…

General Relativity and Quantum Cosmology · Physics 2015-05-13 Adrian P. Gentle

The precise tuning required to observe critical phenomena in gravitational collapse poses a challenge for most numerical codes. First, threshold estimation searches may be obstructed by the appearance of coordinate singularities, indicating…

General Relativity and Quantum Cosmology · Physics 2024-09-24 Daniela Cors , Sarah Renkhoff , Hannes R. Rüter , David Hilditch , Bernd Brügmann

We propose a stochastic conditional gradient method (CGM) for minimizing convex finite-sum objectives formed as a sum of smooth and non-smooth terms. Existing CGM variants for this template either suffer from slow convergence rates, or…

Machine Learning · Computer Science 2022-04-19 Gideon Dresdner , Maria-Luiza Vladarean , Gunnar Rätsch , Francesco Locatello , Volkan Cevher , Alp Yurtsever

Many problems in astrophysics cover multiple orders of magnitude in spatial and temporal scales. While simulating systems that experience rapid changes in these conditions, it is essential to adapt the (time-) step size to capture the…

Instrumentation and Methods for Astrophysics · Physics 2025-02-19 Veronica Saz Ulibarrena , Simon Portegies Zwart

For a class of spatio-temporal tasks defined by a fragment of Signal Temporal Logic (STL), we construct a nonsmooth time-varying control barrier function (CBF) and develop a controller based on a set of simple optimization problems. Each of…

Systems and Control · Electrical Eng. & Systems 2022-08-24 Adrian Wiltz , Dimos V. Dimarogonas

A power-law distance-dependent biased random walk model with a tuning parameter ($\sigma$) is introduced in which finite mean first passage times are realizable if $\sigma$ is less than a critical value $\sigma_c$. We perform numerical…

Statistical Mechanics · Physics 2018-07-23 Christin Puthur , Prabha Chuphal , Snigdha Thakur , Auditya Sharma

Simulations play a key role for inference in collider physics. We explore various approaches for enhancing the precision of simulations using machine learning, including interventions at the end of the simulation chain (reweighting), at the…

High Energy Physics - Phenomenology · Physics 2023-10-24 Benjamin Nachman , Ramon Winterhalder

Recent works have explored the use of momentum in local methods to enhance distributed SGD. This is particularly appealing in Federated Learning (FL), where momentum intuitively appears as a solution to mitigate the effects of statistical…

Machine Learning · Computer Science 2025-11-26 Riccardo Zaccone , Sai Praneeth Karimireddy , Carlo Masone

In this paper, we study Stochastic Control Barrier Functions (SCBFs) to enable the design of probabilistic safe real-time controllers in presence of uncertainties and based on noisy measurements. Our goal is to design controllers that bound…

Systems and Control · Electrical Eng. & Systems 2022-01-03 Shakiba Yaghoubi , Georgios Fainekos , Tomoya Yamaguchi , Danil Prokhorov , Bardh Hoxha

This paper studies the problem of finite-time convergence to a prescribed safe set for nonlinear systems whose initial states violate the safety constraints. Existing Control Lyapunov-Barrier Functions (CLBFs) can enforce recovery to the…

Systems and Control · Electrical Eng. & Systems 2026-03-27 Anni Li , Yingqing Chen , Christos G. Cassandras , Wei Xiao

This work presents global random walk approximations of solutions to one-dimensional Stefan-type moving-boundary problems. We are particularly interested in the case when the moving boundary is driven by an explicit representation of its…

Numerical Analysis · Mathematics 2024-10-17 Nicolae Suciu , Surendra Nepal , Yosief Wondmagegne , Magnus Ögren , Adrian Muntean

In this work, we obtain performance guarantees for modified-CS and for its improved version, modified-CS-Add-LS-Del, for recursive reconstruction of a time sequence of sparse signals from a reduced set of noisy measurements available at…

Information Theory · Computer Science 2015-01-09 Jinchun Zhan , Namrata Vaswani

The slowly evolving gauge coupling of gauge-fermion systems near the conformal window makes numerical investigations of these models challenging. We consider finite size scaling and show that this often used technique leads to inconsistent…

High Energy Physics - Lattice · Physics 2014-07-30 Anqi Cheng , Anna Hasenfratz , Yuzhi Liu , Gregory Petropoulos , David Schaich

We analyze minimal supersymmetric models in order to determine in what parameter regions with what amount of fine-tuning they are capable of accomodating the LHC-allowed top-stop degeneracy window. The stops must be light enough to enable…

High Energy Physics - Phenomenology · Physics 2014-11-26 Durmus Ali Demir , Cem Salih Un

We present a theoretical analysis of stochastic optimization methods in terms of their sensitivity with respect to the step size. We identify a key quantity that, for each method, describes how the performance degrades as the step size…

Optimization and Control · Mathematics 2026-05-27 Fabian Schaipp , Robert M. Gower , Adrien Taylor

Most sensor calibrations rely on the linearity and steadiness of their response characteristics, but practical sensors are nonlinear, and their response drifts with time, restricting their choices for adoption. To broaden the realm of…

Signal Processing · Electrical Eng. & Systems 2022-08-31 Soumyabrata Talukder , Souvik Kundu , Ratnesh Kumar

Many astrophysical simulations involve extreme dynamic range of timescales around 'special points' in the domain (e.g. black holes, stars, planets, disks, galaxies, shocks, mixing interfaces), where processes on small scales couple strongly…

Instrumentation and Methods for Astrophysics · Physics 2026-05-11 Philip F. Hopkins , Elias R. Most

Convergence failure and slow convergence rate are among the biggest challenges with solving the system of non-linear equations numerically. While using strictly small time steps sizes and unconditionally stable fully implicit scheme…

Numerical Analysis · Mathematics 2024-12-20 Hanyu Li , Mary F. Wheeler

Among other improvements, the Martini 3 coarse-grained force field provides a more accurate description of the solvation of protein pockets and channels through the consistent use of various bead types and sizes. Here, we show that the…

Soft Condensed Matter · Physics 2022-07-27 Balázs Fábián , Sebastian Thallmair , Gerhard Hummer