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arXiv research

A locally-built, LLM-digested index of recent arXiv papers in quant finance, geometry/topology, and statistical ML — keyword search served straight from SQLite on this machine.

168,657 papers · 148 categories

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57114170227 · May 202619922001200920172026
48 results for LQR control

Optimal algorithm for LQR control with improved regret bound.

problem Nonstochastic control with quadratic losses (LQR control).
method Online algorithm with optimal dynamic regret of ildeO(extmax{n1/3TV(M1:n)2/3,1}) ilde{O}( ext{max}\{n^{1/3} \mathcal{TV}(M_{1:n})^{2/3}, 1\}).
result Improves the best known rate of ildeO(n(TV(M1:n)+1)) ilde{O}(\sqrt{n (\mathcal{TV}(M_{1:n})+1)} ) for general convex losses.

TSAC achieves optimal frequentist regret in adaptive control of LQRs.

problem Adaptive control of stabilizable linear-quadratic regulators with unknown dynamics.
method Thompson Sampling (TS) for adaptive control of LQRs, with a novel early exploration strategy.
result Achieves ildeO(T) ilde O(\sqrt{T}) regret, optimal for multidimensional systems.

Finding optimal feedback controllers for nonlinear dynamic systems from data is hard. Recently, Bayesian optimization (BO) has been proposed as a powerful framework for direct controller tuning from experimental trials. For selecting the next query point and finding the global optimum, BO relies on a probabilistic desc…

2017-09-20abs ↗pdf ↗

Algorithm minimizes control regret for non-stationary LQR systems.

problem Control of non-stationary LQR systems with unknown dynamics.
method Adaptive non-stationarity detection and OLS estimator with small bias.
result Achieves optimal dynamic regret of $ ilde{\mathcal{O}}\left(V_T^{2/5}T^{3/5} ight)$.

Efficiently solves exploration-exploitation in LQR using Lagrangian relaxation.

problem Exploration-exploitation dilemma in linear quadratic regulator (LQR) setting.
method Relax optimistic optimization into a constrained extended LQR problem, then solve using Riccati equations.
result Computes εε-optimistic controller efficiently with O(log(1/ε))O\big(\log(1/ε)\big) Riccati equations.

New insights into RL efficiency from managing time discretization.

problem The impact of time discretization on RL methods in continuous-time systems.
method Analysis of Monte-Carlo policy evaluation for LQR systems.
result An optimal choice of temporal resolution for a given data budget improves policy evaluation efficiency.

This manuscript surveys reinforcement learning from the perspective of optimization and control with a focus on continuous control applications. It surveys the general formulation, terminology, and typical experimental implementations of reinforcement learning and reviews competing solution paradigms. In order to compa…

2018-06-25abs ↗pdf ↗

Optimal trading strategy using LQR framework with price mean-reversion.

problem Developing a dynamic trading strategy in a market with linear and quadratic costs.
method Model Predictive Control (MPC) approach to optimize trading curve with positivity constraints.
result Optimal trading curve reacts opportunistically to price changes while satisfying constraints.

New algorithm achieves optimal regret in non-stochastic control, showing stochasticity is not beneficial.

problem Achieving optimal control in non-stochastic systems with adversarial noise.
method Novel online Newton step algorithm adapted to adversarial disturbances, using policy regret bounds.
result Optimal O~(T)\widetilde{\mathcal{O}}(\sqrt{T}) regret achieved in unknown dynamics, poly(logT)\mathrm{poly}(\log T) regret in known dynamics.

Policy gradient methods converge for LQR problems with noisy state dynamics.

problem Finding optimal policies in noisy LQR problems over finite time horizons.
method Policy gradient methods with convergence guarantees for finite time and stochastic state dynamics.
result Global linear convergence for policy gradient methods in LQR problems with weak assumptions.

This paper studies how gradient descent in control systems can perform well on unseen data.

problem The extent of a learned controller's ability to extrapolate to unseen initial states.
method Theoretical study of policy gradient in Linear Quadratic Regulator (LQR) problems, focusing on the role of exploration.
result The performance of a learned controller on unseen initial states depends on the degree of exploration induced by the system.

The paper sets bounds on how much regret is unavoidable in adaptive LQR with unknown B-matrix.

problem Understanding the limits of adaptive LQR with unknown B-matrix.
method Local asymptotic minimax regret lower bounds using van Trees' inequality and Bellman error representation.
result Logarithmic regret is impossible if the parametrization induces an uninformative optimal policy.

We consider Online Convex Optimization (OCO) in the setting where the costs are mm-strongly convex and the online learner pays a switching cost for changing decisions between rounds. We show that the recently proposed Online Balanced Descent (OBD) algorithm is constant competitive in this setting, with competitive rat…

2018-10-23abs ↗pdf ↗

Despite decades of research and recent progress in adaptive control and reinforcement learning, there remains a fundamental lack of understanding in designing controllers that provide robustness to inherent non-asymptotic uncertainties arising from models estimated with finite, noisy data. We propose a robust adaptive …

2020-02-24abs ↗pdf ↗

New bounds for adaptive control in high dimensions without fixed state space.

problem Adaptive control of linear systems in high or infinite dimensions.
method Novel perturbation bound for certainty equivalence, scaling with prediction error.
result First regret bounds for LQR in infinite dimensional systems, independent of ambient dimension.

New algorithm learns LQR with O(T)O(\sqrt{T}) regret using Langevin dynamics and excitation.

problem Learning LQR with a O(T)O(\sqrt{T}) regret bound.
method Thompson sampling with Langevin dynamics and excitation mechanism.
result Achieved O(T)O(\sqrt{T}) regret bound for LQR learning.

Survey of theoretical foundations for policy optimization in control.

problem Understanding the theoretical properties of gradient-based methods in control and reinforcement learning.
method Interdisciplinary review of optimization landscape, convergence, and sample complexity for various control problems.
result Recent theoretical results on stability and robustness in learning-based control.

We study the performance of the certainty equivalent controller on Linear Quadratic (LQ) control problems with unknown transition dynamics. We show that for both the fully and partially observed settings, the sub-optimality gap between the cost incurred by playing the certainty equivalent controller on the true system …

2019-02-21abs ↗pdf ↗

This paper studies accelerations in Q-learning algorithms. We propose an accelerated target update scheme by incorporating the historical iterates of Q functions. The idea is conceptually inspired by the momentum-based accelerated methods in the optimization theory. Conditions under which the proposed accelerated algor…

2019-05-07abs ↗pdf ↗

Learning to control linear systems is statistically hard, especially for underactuated systems.

problem Statistical difficulty of learning to control linear systems, especially underactuated ones.
method Utilized minimax lower bounds and structural assumptions to prove learning complexity can be exponential.
result Learning complexity can be at most exponential with the controllability index of the system.

Survey explores geometric aspects of policy optimization in control systems.

problem Understanding the geometric relationships between control design and optimization.
method Geometric perspective on policy optimization, focusing on parameterization and topology.
result Implications of policy geometry on stability and performance of local search algorithms.

We show LLMs can be locally linear, enabling better control of activations.

problem Suboptimal control of LLM activations during generation.
method Model LLM inference as a linear dynamical system, compute feedback controllers using Jacobians, and adapt classical control theory.
result Robust, fine-grained control of LLM activations across models and tasks.

We consider the problem of online adaptive control of the linear quadratic regulator, where the true system parameters are unknown. We prove new upper and lower bounds demonstrating that the optimal regret scales as Θ~(du2dxT)\widetildeΘ({\sqrt{d_{\mathbf{u}}^2 d_{\mathbf{x}} T}}), where TT is the number of time steps, $d_{\m…

2020-01-27abs ↗pdf ↗

A fundamental challenge in artificial intelligence is to build an agent that generalizes and adapts to unseen environments. A common strategy is to build a decoder that takes the context of the unseen new environment as input and generates a policy accordingly. The current paper studies how to build a decoder for the f…

2019-10-30abs ↗pdf ↗

This work establishes safe reinforcement learning for LQR with nonlinear baselines.

problem Safe reinforcement learning in LQR with unknown dynamics and safety constraints.
method General framework for nonlinear baselines, focusing on 1D spaces.
result Achieves optimal regret bounds for constrained reinforcement learning.

Data-driven control of robotic systems using Koopman operators with error bounds.

problem Real-time control of nonlinear robotic systems with unknown dynamics.
method Constructing a Koopman operator-based linear representation using higher-order derivatives of nonlinear dynamics, with error bounds derived from Taylor series accuracy analysis.
result The Koopman model provides marginally better performance than competing nonlinear modeling methods and can be efficiently controlled using linear control design tools.

New method improves reinforcement learning generalization.

problem Few environments lead to poor generalization in reinforcement learning.
method Integrates sequential structure into representation learning, using a policy similarity metric (PSM) and contrastive embeddings (PSEs).
result PSEs improve generalization across various benchmarks.

Study task-guided exploration in linear dynamical systems, improving sample complexity.

problem Efficiently learning about an environment to complete a specific task.
method Proposed a computationally efficient experiment-design based exploration algorithm.
result Optimally explores the environment, collecting precise information needed to complete the task.