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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.

168,695 papers · 148 categories

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4896143191 · May 202619922001200920172026
48 results for static feedback equivalence

In this paper, we present a structurally flat triangular form which is based on the extended chained form. We provide necessary and sufficient conditions for an affine input system with two inputs to be static feedback equivalent to the proposed triangular form, and thus a sufficient condition for an affine input syste…

2020-02-04abs ↗pdf ↗

The problem of feedback equivalence for control systems is considered. An algebra of differential invariants and criteria for the feedback equivalence for regular control systems are found.

2008-12-07abs ↗pdf ↗

The paper studies symmetry reduction of control systems and its implications for feedback linearization.

problem Understanding symmetry reduction and its effects on feedback linearizability of control systems.
method Generalizing the notion of transversality of Lie group actions, analyzing the geometry of invariant distributions, and extending the S-G-S test.
result Classification of SFL quotients based on geometric properties of the control system and symmetry group.

New framework solves dynamic bilevel optimization problems in reinforcement learning.

problem Dynamic objective functions in reinforcement learning and human feedback.
method Principled penalty-based methods for bilevel reinforcement learning.
result Demonstrated effectiveness of penalty-based algorithms in simulations.

Trajectories of light rays in a static spacetime are described by unparametrised geodesics of the Riemannian optical metric associated with the Lorentzian spacetime metric. We investigate the uniqueness of this structure and demonstrate that two different observers, moving relative to one another, who both see the univ…

2011-01-23abs ↗pdf ↗

The paper tackles exact linearization and control of flat discrete-time systems.

problem Exact linearization and control of flat nonlinear discrete-time systems.
method Investigates conditions for choosing new inputs and feedbacks that may depend on forward-shifts of the new input.
result Easily verifiable conditions for choosing a feasible input and a new input that minimizes forward-shifts of the flat output.

The study finds compact vacuum static spaces with positive isotropic curvature are spheres or products of a circle and sphere.

problem Characterizing compact vacuum static spaces with positive isotropic curvature.
method Proving isometric equivalence to spheres or product spaces.
result Compact vacuum static spaces with positive isotropic curvature are isometric to spheres or product spaces.

We consider a continuous-time financial market that consists of securities available for dynamic trading, and securities only available for static trading. We work in a robust framework where a set of non-dominated models is given. The concept of semi-static completeness is introduced: it corresponds to having exact re…

2015-10-07abs ↗pdf ↗

It is shown that any two-dimensional spacetimes with compact Cauchy surfaces can be causally isomorphically imbedded into the two-dimensional Einstein's static universe. Also, it is shown that any two-dimensional globally hyperbolic spacetimes are conformally equivalent to a subset of the two-dimensional Einstein's sta…

2015-01-15abs ↗pdf ↗

Unified framework for analyzing online convex optimization across various settings.

problem Analyzing online convex optimization in different settings and feedback types.
method Unified framework allowing systematic proposal and analysis of meta-algorithms.
result Comparable regret bounds for various feedback types and adversary types.

Establishes a Penrose-type inequality for static spacetimes.

problem Finding a lower bound on the total mass of static spacetimes.
method Analyzes (n+1)-dimensional asymptotically flat standard static spacetimes under timelike convergence condition.
result Extends Penrose-type inequalities to all dimensions and characterizes equality conditions.

New research shows fixed-budget best-arm identification cannot match static oracle performance.

problem Fixed-budget best-arm identification's performance limitations.
method Analysis of various adaptive and static algorithms for best-arm identification.
result For any algorithm, there exists at least one instance where the error decay rate is at most \((1 + \frac{\log(K)}{8})^{-1}\) times that of the static oracle.

New method tackles online DR-submodular maximization with improved regret guarantees.

problem Online maximization of non-monotone DR-submodular functions over down-closed convex sets.
method 1/e-linearization through exponential reparametrization, surrogate potential, and reduction to online linear optimization.
result Achieves O(T1/2)O(T^{1/2}) static regret with single gradient query per round, improving state of the art.

This paper extends a Kyle model to include price-responsive traders, revealing new dynamics and equilibria.

problem Real-world market dynamics involve price-responsive traders, affecting market equilibrium and insider profits.
method Developed a continuous-time Kyle model with two types of price-responsive traders (momentum and contrarian), leading to a forward-backward Riccati system for equilibrium.
result The model shows that feedback effects can lead to multiple equilibria and amplify price informativeness.

Advocates a local feedback approach for RL in unknown systems.

problem Finding optimal feedback laws in unknown nonlinear dynamical systems.
method Searches over a local feedback representation consisting of an open-loop sequence and an optimal linear feedback law.
result Results in highly efficient training and superior performance compared to global methods.

Dynamic regret minimization is shown equivalent to static regret minimization for linear losses.

problem Dynamic regret minimization in online convex optimization.
method Equivalence between dynamic and static regret minimization for linear losses.
result Dynamic regret minimization is equivalent to static regret minimization for linear losses.

The abstract explores connections between reinforcement learning, scaling, and diffusion.

problem Aligning reinforcement learning with human feedback and scaling techniques.
method Clarifying connections between reinforcement learning, scaling, and diffusion.
result Introducing a resampling approach for alignment and reward-directed diffusion models.

In this paper we study some global properties of static potentials on asymptotically flat 33-manifolds (M,g)(M,g) in the nonvacuum setting. Heuristically, a static potential ff represents the (signed) length along MM of an irrotational timelike Killing vector field, which can degenerate on surfaces corresponding to the…

2014-12-02abs ↗pdf ↗

The paper provides guarantees for feedback control with sensor errors.

problem Certifying performance and safety in feedback control systems with sensor errors.
method Solving a supervised learning problem to characterize sensor errors and providing uniform error bounds.
result Finite-time convergence rate on sub-optimality of using a regressor in closed-loop for waypoint tracking.

We show that the flatness of a nonlinear discrete-time system can be checked by computing a unique sequence of involutive distributions. The well-known test for static feedback linearizability is included as a special case. Since the computation of the sequence of distributions requires only the solution of algebraic e…

2019-09-04abs ↗pdf ↗

A control system q˙=f(q,u)\dot{q} = f(q,u) is said to be trivializable if there exists local coordinates in which the system is feedback equivalent to a control system of the form q˙=f(u)\dot{q} = f(u). In this paper we characterize trivializable control systems and control systems for which, up to a feedback transformation, ff a…

2009-02-13abs ↗pdf ↗

New algorithm reduces dynamic regret in time-varying movement costs.

problem Dynamic regret in online convex optimization with time-varying movement costs.
method Introduced a novel algorithm for time-varying movement costs, achieving comparator-adaptive dynamic regret bound.
result Established first comparator-adaptive dynamic regret bound of O~((M2+MPT)(T+tλt))\widetilde{\mathcal{O}}(\sqrt{(M^2+MP_T)(T+\sum_t λ_t)}).

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.

Study online learning with set-valued feedback, showing differences between deterministic and randomized approaches.

problem Online learning with set-valued feedback, where labels are sets rather than single labels.
method Introduced new combinatorial dimensions (Set Littlestone and Measure Shattering) to characterize learnability.
result Characterized deterministic and randomized online learnability, and established bounds for various learning settings.

CausalRM models rewards from user feedback, overcoming noise and bias.

problem Aligning language models with user preferences from noisy, biased feedback.
method Causal-theoretic reward modeling framework addressing noise and bias in observational feedback.
result CausalRM learns accurate reward signals from noisy and biased observational feedback.

New method prevents RLHF alignment collapse by accounting for policy's influence on reward model updates.

problem Iterative RLHF leads to alignment collapse where policies exploit RM's blind spots.
method Foresighted policy optimization (FPO) restores missing steering term via regularization.
result FPO prevents alignment collapse on LLM alignment pipelines using Llama-3.2-1B.

Algorithm minimizes regret in predictive models influenced by their own predictions.

problem Finding near-optimal models under performativity with unknown shifts.
method Developed an algorithm that uses performative feedback to achieve low regret, scaling only with distribution shift complexity.
result Achieved regret bounds scaling with distribution shift complexity, not reward function complexity.

Fairness in machine learning has predominantly been studied in static classification settings without concern for how decisions change the underlying population over time. Conventional wisdom suggests that fairness criteria promote the long-term well-being of those groups they aim to protect. We study how static fairne…

2018-03-12abs ↗pdf ↗

Improved online learning for hidden-convex losses achieves optimal regret.

problem Adversarial online learning with nonconvex losses that become convex after reparameterization.
method Algorithmic equivalence between OGD and OMD on convex losses, with Hessian compatibility condition.
result OGD achieves O(T)\mathcal{O}(\sqrt{T}) regret for hidden-convex losses, matching optimal rate.

New conditional risk measures called conditional generalized quantiles defined and characterized.

problem Developing new risk measures for dynamic risk assessment.
method Propose and characterize conditional generalized quantiles using expected utility model and equivalent conditions.
result Characterized conditional generalized quantiles as well-defined and equivalent to a conditional first order condition.

Many real-world engineering problems rely on human preferences to guide their design and optimization. We present PrefOpt, an open source package to simplify sequential optimization tasks that incorporate human preference feedback. Our approach extends an existing latent variable model for binary preferences to allow f…

2018-01-09abs ↗pdf ↗