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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.

168,742 papers · 148 categories

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12.5%25.0%37.5%50.0% · May 199319922001200920172026
48 results for marginally stable systems

The paper addresses online prediction in marginally stable systems with bounded perturbations.

problem Online prediction in marginally stable linear dynamical systems with adversarial or stochastic perturbations.
method The online least-squares algorithm is used to achieve sublinear regret, with a refined regret analysis and a structural lemma.
result The online least-squares algorithm achieves sublinear regret, with polynomial dependence on the system's parameters.

Study improves curvature estimate for stable marginally outer trapped hypersurfaces with a free boundary.

problem Curvature estimate for stable marginally outer trapped hypersurfaces with a free boundary.
method Iteration argument based on uniform area bound.
result Improved curvature estimate for stable marginally outer trapped hypersurfaces.

Study learns dynamics of linear systems from multiple short trajectories.

problem Learning dynamics of autonomous linear systems from multiple short trajectories.
method Finite sample analysis for stable and unstable systems, adjusting trajectory length for marginally stable systems.
result Learning rate of O(1N)\mathcal{O}(\frac{1}{\sqrt{N}}) for both stable and unstable systems.

ITF improves DSR but inflates curvature, while marginal likelihood reduces it, affecting QoIs.

problem Curvature mismatch between teacher forcing and marginal likelihood in chaotic dynamical systems.
method Comparing objective-induced curvatures of ITF and marginal likelihood in a probabilistic switching augmentation of AL-RNNs.
result Curvature inflation by ITF and reduction by marginal likelihood affect dynamical quantities of interest.

Paper reduces sample complexity for bilinear systems identification to nearly constant.

problem Identifying discrete-time bilinear systems under bounded disturbances.
method Uses trajectory-dependent regressors and polynomial mean-square state growth analysis.
result Proves sample complexity of O~(1/ε)\widetilde{\mathcal O}(1/ε) for estimation error εε.

In this paper, we deal with the problem of marginalization over and conditioning on two disjoint subsets of the node set of chain graphs (CGs) with the LWF Markov property. For this purpose, we define the class of chain mixed graphs (CMGs) with three types of edges and, for this class, provide a separation criterion un…

2014-05-28abs ↗pdf ↗

We derive integral and sup-estimates for the curvature of stably marginally outer trapped surfaces in a sliced space-time. The estimates bound the shear of a marginally outer trapped surface in terms of the intrinsic and extrinsic curvature of a slice containing the surface. These estimates are well adapted to situatio…

2005-12-19abs ↗pdf ↗

In this paper, we analyze the finite sample complexity of stochastic system identification using modern tools from machine learning and statistics. An unknown discrete-time linear system evolves over time under Gaussian noise without external inputs. The objective is to recover the system parameters as well as the Kalm…

2019-03-21abs ↗pdf ↗

Study stability of surfaces in spacetimes, proving new estimates and theorems.

problem Stability of surfaces in spacetime and their applications.
method Variational techniques, Christodoulou-Yau estimate, Cohn-Vossen inequality, global theorem, capillary stability, area inequality, diameter estimate.
result Established new estimates and theorems for stable surfaces in spacetime.

As discussed in the paper, in a matter-filled spacetime, perhaps with positive cosmological constant, a stable marginally outer trapped 2-sphere must satisfy a certain area inquality. Namely, its area must be bounded above by 4π/c4π/c, where c>0c > 0 is a lower bound on a natural energy momentum term. In this note we cons…

2015-03-18abs ↗pdf ↗

In a matter-filled spacetime, perhaps with positive cosmological constant, a stable marginally outer trapped 2-sphere must satisfy a certain area inequality. Namely, as discussed in the paper, its area must be bounded above by 4π/c4π/c, where c>0c > 0 is a lower bound on a natural energy-momentum term. We then consider th…

2015-05-29abs ↗pdf ↗

We investigate the class of σσ-stable Poisson-Kingman random probability measures (RPMs) in the context of Bayesian nonparametric mixture modeling. This is a large class of discrete RPMs which encompasses most of the the popular discrete RPMs used in Bayesian nonparametrics, such as the Dirichlet process, Pitman-Yor p…

2014-07-16abs ↗pdf ↗

New bounds quantify estimation error in kernel-based system identification with unknown hyperparameters.

problem Inaccurate error bounds for kernel-based system identification with unknown hyperparameters.
method Construct a high-probability set for true hyperparameters from marginal likelihood, then find worst-case posterior covariance.
result Proposed bounds contain true model with high probability and verified in simulations.

Proposes a new portfolio optimization method considering reward, dispersion, and asymmetry.

problem Capturing fat-tails and asymmetry in asset return distributions.
method Market model with tempered stable distribution; extended mean-variance optimization.
result Closed-form solutions for VaR and CVaR; efficient frontier extended to three dimensions.

Estimates multiple linear systems on a graph with smoothness constraints.

problem Joint estimation of multiple linear systems under graph smoothness constraints.
method Proposes estimators for joint estimation of system matrices with error bounds.
result MSE converges to zero as mm increases, typically polynomially fast w.r.t mm.

We address the problem of learning the parameters in graphical models when inference is intractable. A common strategy in this case is to replace the partition function with its Bethe approximation. We show that there exists a regime of empirical marginals where such Bethe learning will fail. By failure we mean that th…

2012-02-14abs ↗pdf ↗

The aim of this paper is to collect some facts about the blowup of Jang's equation. First, we discuss how to construct solutions that blow up at an outermost MOTS. Second, we exclude the possibility that there are extra blowup surfaces in data sets with non-positive mean curvature. Then we investigate the rate of conve…

2007-11-29abs ↗pdf ↗

Efficient algorithm predicts unknown linear systems with long-term memory.

problem Predicting unknown and partially observed linear dynamical systems with long-term memory.
method Bounding the generalized Kolmogorov width of the Kalman filter model using spectral methods and conducting tight convex relaxation.
result Competes with Kalman filter in hindsight with only logarithmic regret.

Stability is an important aspect of a classification procedure because unstable predictions can potentially reduce users' trust in a classification system and also harm the reproducibility of scientific conclusions. The major goal of our work is to introduce a novel concept of classification instability, i.e., decision…

2017-01-20abs ↗pdf ↗

Gradient descent biases towards stable rank networks for nearly-orthogonal data.

problem Understanding implicit bias in non-smooth neural networks trained by gradient descent.
method Analysis of two-layer ReLU and leaky ReLU networks trained by gradient descent on nearly-orthogonal data.
result Gradient descent biases towards networks with stable rank and uniform margin for nearly-orthogonal data.

The paper optimizes portfolios using relative tail risk measures.

problem Optimizing portfolios with respect to relative tail risk.
method Analytic forms of portfolio CoVaR and CoCVaR derived on a market model. Monte-Carlo simulation for CoCVaR and marginal contributions. Risk budgeting method applied.
result Derivation of analytic forms for CoVaR and CoCVaR, and their marginal contributions.

The OLS estimator optimally identifies stable linear systems with a finite number of samples.

problem Identifying stable linear systems with a finite number of samples.
method Finite-time analysis of the Ordinary Least Squares (OLS) estimator for stable linear systems.
result The OLS estimator achieves optimal sample complexity for stable systems, matching existing lower bounds up to universal factors.

Bayesian deep neural networks converge to processes with α-stable marginals under infinite variance weights.

problem Representation learning in deep kernel processes is hindered by deterministic covariance kernels.
method Showed convergence to α-stable processes with conditionally Gaussian representations in infinite-width networks.
result Conditional random covariance kernels can be recursively linked, even if the process is α-stable.

Study identifies stable configurations of intertwined threads with repulsive interactions.

problem Stable configurations of entangled systems with repulsive interactions.
method Analysis of steepest descent flow of an energy functional.
result Existence and uniqueness of stable configuration of two layers drifting apart at t1/3t^{1/3} rate.

3MSBM learns smooth trajectories from multiple snapshots.

problem Capturing long-range temporal dependencies in complex systems.
method Lifts dynamics to phase space, generalizes stochastic bridges to multi-marginal conditional problems, learns transport maps preserving intermediate marginals.
result Significantly improves convergence and scalability in capturing complex dynamics.

The paper develops Kalman filters for unknown systems with sample complexity bounds.

problem Designing Kalman filters for systems with unknown parameters and noise.
method Combines system identification with Kalman filter design, ensuring robustness and sub-optimality guarantees.
result Proves sub-optimality guarantees for both Certainty Equivalent and robust Kalman filters with sample complexity bounds.

The paper proves stability of certain singularities in integrable systems.

problem Stability of singularities in integrable systems under perturbations.
method Analytic and smooth perturbations of completely integrable systems, connectedness condition.
result Non-degenerate singular fibers are structurally stable under small perturbations.

This work extracts stochastic dynamical systems with α\alpha-stable Lévy noise.

problem Extracting data-driven governing laws of dynamical systems with non-Gaussian noise.
method End-to-end deep learning approach for learning drift and diffusion coefficients for α\alpha-stable Lévy noise.
result Effectiveness of the method confirmed by numerical experiments.

Study of supervised learning from multiple non-independent sequences.

problem Efficient learning from many non-independent sequences.
method Generalizes conditions for efficient learning from independent examples and single auto-correlated sequences.
result Error rate changes from Θ(n/mT)Θ(n / m T) to Ω(n2/m2T)Ω(n^2 / m^2 T) as the number of trajectories increases.