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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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491317 · Mar 202619922001200920172026
48 results for Unconstrained

Unconstrained MLIPs outperform constrained ones in accuracy and speed.

problem Improving the efficiency and accuracy of machine-learned interatomic potentials.
method Investigated unconstrained models trained on large datasets compared to physically constrained models.
result Unconstrained MLIPs can be superior in accuracy and speed compared to physically constrained models.

New approach reduces unconstrained linear bandits to simpler optimization problems.

problem Unconstrained linear bandits problem.
method Perturbation-based approach combined with comparator-adaptive OLO algorithms.
result First high-probability guarantees for both static and dynamic regret in unconstrained linear bandits.

We clarify what fairness guarantees we can and cannot expect to follow from unconstrained machine learning. Specifically, we characterize when unconstrained learning on its own implies group calibration, that is, the outcome variable is conditionally independent of group membership given the score. We show that under r…

2018-08-29abs ↗pdf ↗

Unconstrained models learn physical symmetries effectively with simple data augmentation.

problem Ensuring physical symmetries in machine learning models.
method Rigorous metrics to measure symmetry content, data augmentation strategy, architectural analysis.
result Unconstrained models can learn approximate equivariant behavior with simple data augmentation.

The paper explores solving inverse problems for ODEs with and without constraints.

problem Understanding when second order ODEs can represent Lagrangian models with or without constraints.
method Geometric techniques to address the inverse problem for both constrained and unconstrained systems of second order ODEs.
result The constrained case presents more ambiguities and complexities than the unconstrained one.

Proposes ConstraintMatch for semi-supervised clustering with unconstrained data.

problem Leveraging unconstrained data alongside constraints for clustering models.
method Semi-supervised context with pseudo-constraining and pseudo-labeling mechanisms.
result Demonstrates effectiveness of ConstraintMatch over baselines.

This paper extends neural collapse to class-imbalanced datasets using an unconstrained ReLU feature model.

problem Understanding neural collapse in class-imbalanced datasets with cross-entropy loss.
method Generalized neural collapse to class-imbalanced settings using an unconstrained ReLU feature model.
result Class-means converge to orthogonal vectors with different lengths, and classifier weights align to these vectors.

New algorithms reduce online learning regret by tracking gradient variation.

problem Online learning with unconstrained losses and gradient variation.
method Parameter-free algorithms with adaptive updates for LL-smooth convex losses.
result Regret bounds of order O~(uVT(u)+Lu2+G4)\widetilde{O}(\|u\|\sqrt{V_T(u)} + L\|u\|^2+G^4) achieved without prior knowledge of comparator norm or Lipschitz constant.

A new L-BFGS method tackles large-scale optimization with fewer evaluations.

problem Efficiently solving large-scale unconstrained optimization problems.
method Proposes a regularized L-BFGS method with line search techniques.
result Shows global convergence and robust performance in numerical tests.

New algorithm minimizes cumulative loss in dynamic linear bandits without prior knowledge of comparator switches.

problem Minimizing cumulative loss in dynamic linear bandits with unknown number of switches.
method Combining several bandit algorithms to adapt to unknown number of switches without prior knowledge.
result First algorithm achieving optimal regret guarantee of O(d(1+ST)T)\mathcal{O}\big(\sqrt{d(1+S_T) T}\big) up to poly-logarithmic terms.

We propose an online convex optimization algorithm (RescaledExp) that achieves optimal regret in the unconstrained setting without prior knowledge of any bounds on the loss functions. We prove a lower bound showing an exponential separation between the regret of existing algorithms that require a known bound on the los…

2017-03-07abs ↗pdf ↗

VAV method optimizes learning rate for faster, stable SGD convergence.

problem Optimizing learning rate for efficient and stable machine learning models.
method Energy-based self-adaptive learning rate with auxiliary variable rr.
result VAV method achieves faster convergence and superior stability with larger learning rates.

We consider a variant of online convex optimization in which both the instances (input vectors) and the comparator (weight vector) are unconstrained. We exploit a natural scale invariance symmetry in our unconstrained setting: the predictions of the optimal comparator are invariant under any linear transformation of th…

2017-08-23abs ↗pdf ↗

Solves VaR-constrained portfolio optimization in markets with stochastic volatility.

problem Optimizing portfolio in markets with stochastic volatility under VaR constraints.
method Dynamic programming approach to Heston's stochastic volatility model.
result Optimal investment strategy linked to unconstrained problem via a vega-neutral derivative.

Cookbook transforms constrained statistical inference into unconstrained problems.

problem Transforming constrained statistical inference into unconstrained problems.
method Bijective and diffeomorphisms parametrizations.
result Maintains statistical inference properties like identifiability.

DP-GD achieves dimension-independent convergence for unconstrained private GLMs.

problem Differentially private empirical risk minimization for unconstrained GLMs.
method Differentially private gradient descent (DP-GD).
result DP-GD achieves an excess empirical risk of $ ilde O\left(\sqrt{ exttt{rank}}/εn ight)$ for unconstrained GLMs.

Yau's Affine Normal Descent optimizes smooth unconstrained problems with geometrically adapted directions.

problem Optimizing smooth unconstrained problems with geometrically adapted directions.
method Yau's Affine Normal Descent (YAND) uses the equi-affine normal of level-set hypersurfaces as search directions.
result YAND converges globally under standard smoothness assumptions and locally quadratically near nondegenerate minimizers.

Study optimal portfolio management with periodic evaluations in stochastic models, considering convex constraints.

problem Optimal portfolio management under ratio-type periodic evaluations in stochastic factor models with convex trading constraints.
method Transformed infinite horizon optimal control problem into an auxiliary terminal wealth optimization problem. Introduced an auxiliary unconstrained optimization problem in a modified market model. Used martingale duality approach to establish dual minimizer and optimal unconstrained wealth process.
result Derived and verified the optimal constrained portfolio process for the original problem over an infinite horizon.

Adam converges with high probability under unconstrained non-convex smooth stochastic optimizations.

problem Theoretical limitations of Adam's convergence under unconstrained non-convex smooth stochastic optimizations.
method Deep analysis of Adam's convergence rate under affine variance noise, without bounded gradient assumptions.
result Adam converges to the stationary point with a high probability rate of $\mathcal{O}\left({ m poly}(\log T)/\sqrt{T} ight)$.

Paper analyzes regret bounds for unconstrained online optimization.

problem Minimizing regret in dynamic online learning for strongly convex and smooth functions.
method Preconditioned OGD, Online Optimistic Newton (OON), multiple gradient queries.
result Achieves O(C2,T)O(C^*_{2,T}) regret bound with one gradient query per round.

New methods solve complex optimization problems in machine learning.

problem Challenges in stochastic bilevel optimization with constraints and high variables.
method Inexact bilevel stochastic gradient methods for constrained and unconstrained lower-level problems.
result Comprehensive convergence theory for both unconstrained and constrained cases.

New sparse Gaussian process method tackles unconstrained regression problems.

problem Dealing with physical systems that satisfy inequality constraints.
method Extends constrained Gaussian process by redefining hat basis functions.
result Reduces computational complexity from O(n3)O(n^{3}) to O(nm2)O(nm^{2}).

The paper studies knot densities under various constraints and degenerations.

problem Understanding knot densities under different constraints and their degenerations.
method Introduces and analyzes unconstrained and ropelength-windowed pp-densities of knot types.
result The degenerations in the unconstrained theory and the introduction of ropelength-windowed densities.

We consider minimizing a nonconvex, smooth function ff on a Riemannian manifold M\mathcal{M}. We show that a perturbed version of Riemannian gradient descent algorithm converges to a second-order stationary point (and hence is able to escape saddle points on the manifold). The rate of convergence depends as 1/ε21/ε^2 o…

2019-06-18abs ↗pdf ↗

This paper extends neural collapse to imbalanced data under cross-entropy loss.

problem Analyzing neural collapse in deep networks with imbalanced data.
method Using the unconstrained feature model and cross-entropy loss, the paper studies neural collapse in imbalanced datasets.
result Feature vectors within the same class collapse to a single mean vector, but angles between them depend on sample size.

Proposes an evolutionary approach to fitting acyclic VAR models.

problem Cycles in multivariate time series systems obscure hierarchical analysis.
method Evolutionary approach to fitting acyclic VAR processes with hierarchical representation.
result Outperforms unconstrained models and captures key structural properties.

Paper proves fair classification can be done via simple thresholding.

problem Achieving fair binary classification subject to group fairness constraints.
method Proves Bayes optimal fair learning rule is a group-wise thresholding rule over the Bayes regressor with randomization.
result Proposes an efficient unconstrained optimization algorithm for post-processing fair classification.

We study optimization methods for solving the maximum likelihood formulation of independent component analysis (ICA). We consider both the the problem constrained to white signals and the unconstrained problem. The Hessian of the objective function is costly to compute, which renders Newton's method impractical for lar…

2018-06-25abs ↗pdf ↗

Develops methods for estimating constrained function-valued parameters in infinite-dimensional models.

problem Estimating function-valued parameters with structural constraints in complex models.
method Characterizes constrained solutions as minimizers of penalized population risk, using a Lagrange-type formulation and path through unconstrained space.
result Proposes estimators that achieve optimal risk and constraint satisfaction, applicable across various statistical learning approaches.

Study uses RL to optimize investment with financial constraints, showing exploration benefits.

problem Optimal investment with financial constraints in continuous time.
method Reinforcement learning framework, focusing on Gaussian and truncated Gaussian distributions.
result Exploration leads to more dispersed wealth distribution with heavier tails, especially with smaller exploration parameters.

Monotonic neural networks have recently been proposed as a way to define invertible transformations. These transformations can be combined into powerful autoregressive flows that have been shown to be universal approximators of continuous probability distributions. Architectures that ensure monotonicity typically enfor…

2019-08-14abs ↗pdf ↗

Quantum computing improves feature selection in machine learning.

problem Optimizing feature selection in machine learning problems.
method Formulated feature selection as a QUBO problem and compared quantum and classical methods.
result Quantum computing can outperform classical methods in feature selection, depending on data set.

Paper proposes DG-ETC for online submodular maximization with stochastic bandit feedback.

problem Online unconstrained submodular maximization with stochastic bandit feedback.
method Double-Greedy - Explore-then-Commit (DG-ETC) approach.
result DG-ETC achieves logarithmic regret O(dlog(dT))O(d\log(dT)) for 1/21/2-approximate pseudo-regret.

Neural networks have been used prominently in several machine learning and statistics applications. In general, the underlying optimization of neural networks is non-convex which makes their performance analysis challenging. In this paper, we take a novel approach to this problem by asking whether one can constrain neu…

2017-10-05abs ↗pdf ↗

Properties of steady compressible flow for which geometric constraints have been placed on the potential function are derived, under hypotheses on the flow density and the singular set. Some related unconstrained problems are also considered, including the estimation of a class of fields having nonzero vorticity.

2003-02-27abs ↗pdf ↗

Investigates portfolio optimization with and without gearing constraints.

problem Improving portfolio weights for better alignment with expected returns.
method Extends the alpha-weight angle bound to include gearing constraints and uses theoretical arguments and simulations.
result Equally weighted portfolios are not preferable to mean-variance portfolios even with poor forecast ability and a badly conditioned covariance matrix.

Despite significant progress made over the past twenty five years, unconstrained face verification remains a challenging problem. This paper proposes an approach that couples a deep CNN-based approach with a low-dimensional discriminative embedding learned using triplet probability constraints to solve the unconstraine…

2016-04-19abs ↗pdf ↗

Study shows 'Ordinal Neural Collapse' in deep OR tasks, revealing simple geometric relationships.

problem Understanding neural collapse in deep Ordinal Regression tasks.
method Combining cumulative link models and Unconstrained Feature Model to investigate neural collapse.
result Demonstrates 'Ordinal Neural Collapse' (ONC) with three key properties.