Research
On-device research index

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

Trend · papers per month

5101520 · Feb 202619922001200920172026
48 results for Self-concordant barriers

Many problems in statistical learning, imaging, and computer vision involve the optimization of a non-convex objective function with singularities at the boundary of the feasible set. For such challenging instances, we develop a new interior-point technique building on the Hessian-barrier algorithm recently introduced …

2019-11-04abs ↗pdf ↗

Interior-point methods adapted for manifolds, achieving similar optimization results.

problem Optimizing on manifolds with self-concordant barriers.
method Generalization of self-concordance to Riemannian manifolds, path-following method analysis.
result Local quadratic convergence of Newton's method and standard complexity guarantees.

RHMC improves sampling polytopes defined by inequalities with barriers.

problem Sampling polytopes defined by inequalities efficiently.
method Riemannian Hamiltonian Monte Carlo (RHMC) with a hybrid of Lewis weights and logarithmic barriers.
result RHMC achieves mixing rate of ildeO(m1/3n4/3) ilde O(m^{1/3}n^{4/3}) for polytopes defined by mm inequalities in Rn\R^n.

Unified analysis of online optimization with self-concordant barriers, improving regret bounds.

problem Online convex optimization with specific loss functions.
method Online mirror descent with self-concordant barriers and logarithmic loss.
result Improved regret bounds for online portfolio selection and quantum state learning.

Algorithm for online decision making with unknown dynamics and aggregate feedback.

problem Online decision making with unknown dynamics and aggregate bandit feedback.
method Developed an algorithm based on online mirror descent with a self-concordant barrier regularization and an increasing learning rate schedule.
result Achieved O(K)O(\sqrt{K}) regret for the online Markov Decision Process with KK episodes.

New approach for online learning with adaptive adversaries, simpler and more effective.

problem Online learning with adaptive adversaries, especially in bandits and MDPs.
method Uses standard unbiased estimators and a simple increasing learning rate schedule, aided by logarithmically homogeneous self-concordant barriers and strengthened Freedman's inequality.
result First high-probability regret bounds for adversarial bandits and MDPs, resolving open problems.

Unified meta-algorithm improves average performance across similar tasks in adversarial bandits.

problem Improving performance across multiple similar tasks in adversarial bandit settings.
method Unified meta-algorithm for multi-armed bandits and bandit linear optimization, tuning initialization, step-size, and entropy parameters.
result Unified meta-algorithm yields setting-specific guarantees for MAB and BLO, improving task-averaged regret.

New algorithm reduces prediction errors across various loss functions.

problem Online forecasting algorithms' inability to adapt to different loss functions.
method Design of a novel Follow-the-Perturbed-Leader (FTPL) algorithm with self-concordant noise.
result Simultaneously achieves ildeO(T) ilde O(\sqrt{T}) regret for bounded proper losses and O(logT)O(\log T) regret for bounded smooth proper losses.

New bounds for online portfolio selection without smoothness assumptions.

problem Online portfolio selection with non-Lipschitz, non-smooth losses.
method Data-dependent bounds using novel smoothness characterizations and FTRL with self-concordant regularizers.
result Achieves logarithmic regrets when data is 'easy' and sublinear worst-case regrets.

The Riemannian Langevin Algorithm samples from manifolds efficiently.

problem Sampling from distributions on manifolds with log-Sobolev inequality.
method Riemannian Langevin Algorithm, log-Sobolev inequality, self-concordance extension, stochastic smoothness bounding.
result The Riemannian Langevin Algorithm converges rapidly to the target density.

We propose a new proximal, path-following framework for a class of constrained convex problems. We consider settings where the nonlinear---and possibly non-smooth---objective part is endowed with a proximity operator, and the constraint set is equipped with a self-concordant barrier. Our approach relies on the followin…

2016-03-05abs ↗pdf ↗

A new sampling method for log-concave distributions with warm starts and barriers.

problem Sampling from log-concave distributions constrained by convex bodies with barriers.
method Robust sampling framework using spectral approximations to Hessian of barrier functions.
result Improved mixing times for polytopes and spectrahedra, faster than previous methods.

We study the smooth structure of convex functions by generalizing a powerful concept so-called self-concordance introduced by Nesterov and Nemirovskii in the early 1990s to a broader class of convex functions, which we call generalized self-concordant functions. This notion allows us to develop a unified framework for …

2017-03-14abs ↗pdf ↗

Improved Frank-Wolfe algorithm for generalized self-concordant functions converges quickly.

problem Efficiently solving learning problems with generalized self-concordant objectives.
method Simple Frank-Wolfe variant with open-loop step size strategy γt=2/(t+2)γ_t = 2/(t+2).
result Achieves O(1/t)\mathcal{O}(1/t) convergence rate for primal and Frank-Wolfe gaps.

New insights into natural exponential families improve regret bounds for bandit problems.

problem Improving regret bounds for bandit problems with subexponential tails.
method Proving self-concordance for natural exponential families and applying to bandits.
result Optimistic algorithms for generalized linear bandits have second-order regret bounds that are free of an exponential dependence on problem parameters.

New method solves constrained self-concordant minimization problems efficiently.

problem Constrained self-concordant minimization problems.
method Newton Frank-Wolfe method using linear minimization oracles.
result The method uses nearly the same number of linear minimization calls as the Frank-Wolfe method.

New bounds on minimax regret for sequential probability assignment using logarithmic loss.

problem Minimizing regret in sequential probability assignment against arbitrary experts.
method Using self-concordance property of logarithmic loss to derive tight bounds.
result Tight bounds on minimax regret for various expert classes.

We propose a variable metric framework for minimizing the sum of a self-concordant function and a possibly non-smooth convex function, endowed with an easily computable proximal operator. We theoretically establish the convergence of our framework without relying on the usual Lipschitz gradient assumption on the smooth…

2013-08-13abs ↗pdf ↗

Meta-learning improves performance across similar tasks in adversarial bandit settings.

problem Improving performance across multiple similar tasks in adversarial bandit scenarios.
method Designing meta-algorithms that combine outer learners to tune hyperparameters of inner learners for MAB and BLO.
result Meta-algorithms improve task-averaged regret for MAB and BLO, showing direct relationship with action space-dependent measures.

Improved prediction algorithm for 'easy' sequences with reduced regret.

problem Prediction with expert advice for 'easy' sequences.
method Variant of NormalHedge algorithm using second-order εε-quantile regret bound.
result Second-order εε-quantile regret bound of O(VTlog(VT/ε))O\big(\sqrt{V_T \log(V_T/ε)}\big) for VT>logNV_T > \log N.

We consider the class of convex minimization problems, composed of a self-concordant function, such as the logdet\log\det metric, a convex data fidelity term h()h(\cdot) and, a regularizing -- possibly non-smooth -- function g()g(\cdot). This type of problems have recently attracted a great deal of interest, mainly due to th…

2014-05-13abs ↗pdf ↗

The classical asymptotic theory for parametric MM-estimators guarantees that, in the limit of infinite sample size, the excess risk has a chi-square type distribution, even in the misspecified case. We demonstrate how self-concordance of the loss allows to characterize the critical sample size sufficient to guarantee …

2018-10-16abs ↗pdf ↗

The paper calculates prices for multi-step barrier options under the Black-Scholes model.

problem Calculating prices for multi-step barrier options with varying barriers and time steps.
method Derives a general, explicit expression for option prices using the Black-Scholes model and a multi-step reflection principle.
result Derives a multi-step reflection principle that generalizes the reflection principle of Brownian motion.

A time-dependent double-barrier option is a derivative security that delivers the terminal value φ(ST)φ(S_T) at expiry TT if neither of the continuous time-dependent barriers $b_\pm:[0,T]\to \RR_+$ have been hit during the time interval [0,T][0,T]. Using a probabilistic approach we obtain a decomposition of the barrier opti…

2008-09-10abs ↗pdf ↗

We discuss the pricing methodology for Bonus Certificates and Barrier Reverse-Convertible Structured Products. Pricing for a European barrier condition is straightforward for products of both types and depends on an efficient interpolation of observed market option pricing. Pricing products We discuss the pricing metho…

2016-07-31abs ↗pdf ↗

Efficient semi-analytic methods for pricing double barrier options with time-dependent parameters.

problem Pricing and calibration of double barrier options with time-dependent parameters.
method Two approaches: General Integral transform method and Heat Potential method.
result Semi-analytic techniques are more efficient for pricing double barrier options than traditional numerical methods.

We provided an analytical representation of the price of a barrier option with one type of special moving barrier. We consider the case that risk free rate, dividend rate and stock volatility are time dependent. We get a pricing formula and put call parity for barrier option when the moving barrier has a special relati…

2013-03-06abs ↗pdf ↗

Improved confidence bounds for linear logistic model with applications to bandits.

problem Improving confidence bounds for linear logistic model.
method Self-concordant analysis of the logistic loss to avoid dependence on worst-case variance.
result Significant improvement in confidence bounds, avoiding dependence on 1/κ1/κ.

We compute the effect of concordance surgery, a generalization of knot surgery defined using a self-concordance of a knot, on the Ozsváth-Szabó 4-manifold invariant. The formula involves the graded Lefschetz number of the concordance map on knot Floer homology. The proof uses the sutured Floer TQFT, and a version of su…

2018-04-17abs ↗pdf ↗