New method connects leverage scores and kernel density, revealing a decreasing relationship.
problem Understanding the relationship between leverage scores and kernel density.
method Introducing regularized Christoffel functions to study leverage scores for kernel methods.
result Quantitatively describes a decreasing relation between leverage score and population density for a broad class of kernels.
Study optimal consumption and investment strategies with leverage constraints using Epstein-Zin utility.
problem Optimal portfolio choice under leverage constraints and Epstein-Zin utility.
method Established viscosity solution to HJB equation, demonstrated smoothness, characterized optimal strategies, derived explicit solutions.
result Explicit solutions for optimal consumption and investment strategies under leverage constraints.
New active learning methods use statistical leverage scores to select examples efficiently.
problem Efficiently selecting labeled examples for high model accuracy with limited labeled data.
method Proposes ALEVS and DBALEVS methods based on statistical leverage scores.
result DBALEVS selects diverse, representative examples efficiently.
Study shows TAR model captures leverage effect in financial series.
problem Capturing leverage effect in financial series.
method Threshold autoregressive (TAR) model with Bayesian approach.
result Analytical expressions for TAR model moments derived.
Study on market data relaxation and correlations in mean-reverting models.
problem Analyzing relaxation and correlations in market data using mean-reverting models.
method Derived closed-form expressions for correlation functions and leverage for various models, applied eigenvalue analysis for the Heston model, tested findings on historic financial markets data.
result Agreement between general analysis and Heston model's eigenvalue analysis for correlation function.
A new robust PCA method uses Innovation Search and Leverage Scores.
problem Outlier detection and robust PCA in data clustering.
method Innovation Search and Leverage Scores.
result The method provides theoretical guarantees and outperforms existing algorithms.
We study in details the skew of stock option smiles, which is induced by the so-called leverage effect on the underlying -- i.e. the correlation between past returns and future square returns. This naturally explains the anomalous dependence of the skew as a function of maturity of the option. The market cap dependence…
New method improves volatility forecasts by relaxing linear assumption in leverage effect.
problem Empirical evidence contradicts the leverage effect's ability to improve volatility forecasts.
method Developed a Bayesian stochastic volatility framework with nonlinear leverage effects.
result Nonlinear leverage effect improves predictive performance for 89% of stocks.
Estimates volatility of volatility and leverage effect using high-frequency options data.
problem Estimating volatility of volatility and leverage effect from high-frequency options data.
method Model-free estimators using characteristic function of price increments and spot volatility.
result Developed feasible inference methods for estimating volatility of volatility and leverage effect.
The paper uses tensor decompositions to improve neural network models for tree data.
problem Encoding structural knowledge from tree-structured data efficiently.
method Introduces new aggregation functions using Canonical and Tensor-Train decompositions.
result Proposed models outperform traditional methods on tree classification tasks.
Derives new equations for stochastic volatility models.
problem Modeling local-stochastic-volatility models and their derivatives.
method Conditional forward equation, Dupire stochastic PDE, rolling expiry vanilla option SPDE.
result New equations for LSV models and their derivatives.
Optimizes banks' capital allocation using linear approximations.
problem Maximizing return on capital for banks' business units.
method Formulated as mean variance optimization with linear approximations to cost functions.
result Analytical solution for optimal leveraged balance sheet and risk weighted assets.
Optimizes portfolios with utility theory, diversification, and leverage.
problem Finding optimal portfolio allocation strategies.
method Utility theory, exponential and logarithmic utilities, compound probability distributions, maximum expected utility, generalized mean-variance.
result Enhanced portfolio allocation strategies with natural explanations.
Optimizes leveraged staking strategies in decentralized finance.
problem Maximizing returns on staked assets in decentralized lending platforms.
method Developed a mathematical framework to optimize leveraged staking strategies, reducing the multi-market problem to convex allocation over market exposures.
result Rebalanced leveraged positions can achieve up to 6.2% APY, significantly higher than unleveraged staking.
In modern portfolio theory, the balancing of expected returns on investments against uncertainties in those returns is aided by the use of utility functions. The Kelly criterion offers another approach, rooted in information theory, that always implies logarithmic utility. The two approaches seem incompatible, too loos…
This paper provides a framework for modeling the financial system with multiple illiquid assets when liquidation of illiquid assets is caused by failure to meet a leverage requirement. This extends the network model of Cifuentes, Shin & Ferrucci (2005) which incorporates a single asset with fire sales and capital adequ…
Efficiently approximates statistical leverage scores for faster KRR.
problem Accurately estimating statistical leverage scores for fast KRR.
method Analytic formula for statistical leverage scores, leveraging kernel spectral density.
result Linear time approximation with theoretical guarantees, significantly faster than existing methods.
Analyzes long-term growth rate of leveraged ETFs using martingale extraction.
problem Determines long-term growth rate of leveraged ETFs under various models.
method Develops analytical approach using martingale extraction and eigenpair of infinitesimal generator.
result Derives explicit long-term growth rates for different reference asset models.
Enhanced tree-based classifiers use derivatives and geometry for better function classification.
problem Improving classification of high-dimensional time series data.
method Integrates Functional Data Analysis with tree-based ensemble techniques, leveraging derivative and geometric features.
result Significant improvements over traditional approaches in function classification.
New image restoration method using localized patches and external databases.
problem Image restoration challenges.
method Localized structured prediction and non-linear multi-task learning for optimizing a penalized energy function.
result Strong statistical guarantees and practical effectiveness demonstrated on various image restoration problems.
New methods identify causal effects without needing complete proxy variables.
problem Identifying causal effects in the presence of unmeasured confounders.
method Partial identification methods that do not require completeness of proxy variables.
result Obtain bounds on causal effects using available proxy variables.
New method estimates and optimizes policy differences using orthogonal learning.
problem Offline reinforcement learning with safety concerns and cost limitations.
method Dynamic R-learner for estimating and optimizing Qπ(s,1)−Qπ(s,0), leveraging orthogonal estimation. result Consistent policy optimization with improved convergence rates.
Proposes robust features for adversarial attacks.
problem Learning robust models to adversarial perturbations is hard.
method Develops robust features by leveraging spectral properties of dataset geometry.
result Establishes strong connections between robust features and spectral geometry.
NeuTSFlow models continuous functions behind time series forecasting.
problem Forecasting treats time series as discrete sequences, ignoring their continuous nature.
method NeuTSFlow uses Neural Operators to learn the transition between historical and future function families.
result NeuTSFlow outperforms traditional methods in forecasting accuracy and robustness.
Develops a statistical arbitrage strategy with stop-loss and leverage for energy markets.
problem Optimizing trading strategies in high-frequency energy markets with stop-loss and leverage.
method Analytical approach using mean-reverting processes and optimal trading strategies.
result Analytical expressions for expected First-Exit-Times and long-run returns of the strategy.
The paper presents a method to recover high-resolution signals from low-resolution measurements.
problem Recovering high-resolution signals from low-resolution indirect measurements.
method Combining generalized sampling and functional principal component analysis.
result High-resolution recovery is possible under certain conditions and with a sufficiently large training set.
Paper proposes exploiting Q function structures for better planning and RL.
problem Value-based methods in planning and RL.
method Exploiting low-rank structure of Q function using Matrix Estimation techniques.
result Improved planning and RL performance on 'low-rank' tasks.
Enhances clustering for functional data, robust to outliers.
problem Challenges of clustering infinite-dimensional functional data and outlier sensitivity.
method Extends OCLUST algorithm to handle functional data, trimming outliers.
result Strong performance in clustering and outlier identification on simulated and real-world datasets.
New algorithms use randomized value functions for efficient exploration in reinforcement learning.
problem Improving exploration in reinforcement learning algorithms.
method Leverage randomized value functions to guide exploration.
result Proved a regret bound for statistical efficiency with tabular representation.
Quant GANs model financial time series using GANs with TCNs.
problem Modeling financial time series with stochastic processes.
method Quant GANs use a generator and discriminator with TCNs to capture long-range dependencies.
result Quant GANs generate financial time series with distributional and dependence properties in high fidelity.
New method learns discrete graph diffusion via free-energy gradient flows.
problem Challenges in translating continuous diffusion models to discrete spaces.
method Proposes a novel computational approach using a specific metric on the simplex.
result Recover the underlying functional for various graph classes.
Derives PF-ODE for infinite-dimensional functions, improving function generation tasks.
problem Efficient inference in infinite-dimensional diffusion models.
method Derives PF-ODE in infinite-dimensional function spaces.
result Reduces function evaluations while maintaining sample quality.
Efficiently learns private models using public data.
problem Improving private learning performance with public data.
method Proves computationally efficient algorithms for private learning with public data.
result First computationally efficient algorithms for private learning with public data.
Common asset holdings are widely believed to have been the primary vector of contagion in the recent financial crisis. We develop a network approach to the amplification of financial contagion due to the combination of overlapping portfolios and leverage, and we show how it can be understood in terms of a generalized b…
A new sampling strategy for random Fourier features reduces computation time and improves prediction performance.
problem Efficient generation of random Fourier features for kernel approximation.
method Surrogate leverage weighted sampling guided by kernel alignment, avoiding matrix inversion.
result Time complexity reduced from O(ns^2+s^3) to O(ns^2), comparable or slightly better prediction performance.
This paper proposes an ensemble of Gaussian processes for Bayesian optimization.
problem Optimizing expensive black-box functions with limited evaluations.
method An ensemble of Gaussian processes (EGP) for adaptive surrogate modeling, combined with Thompson sampling (TS) for function sampling.
result The proposed EGP-TS method achieves better optimization results than single-GP approaches.
Method leverages population data to deconvolve unknown noise and model parameters.
problem Deconvolution of unknown observational noise in distributional inversion problems.
method Large data sets from physical systems, modified gradient descent, active learning.
result Simultaneous deconvolution of noise and model parameters.
ORIL learns a reward function from unlabeled data to improve robot learning.
problem Leveraging unlabeled data for robot learning.
method ORIL learns a reward function from demonstrator and unlabeled trajectories, annotates data, and trains an agent via offline reinforcement learning.
result ORIL consistently outperforms BC agents on various robotic tasks.
Bayesian optimization of function networks using intermediate outputs.
problem Efficiently optimizing networks of functions with significant evaluation time.
method Modeling nodes as Gaussian processes and using expected improvement acquisition function.
result Demonstrates superior performance compared to standard Bayesian optimization methods.
Multivariate splines linked to infinitely-wide neural networks with improved numerical performance.
problem Understanding the relationship between multivariate splines and neural networks.
method Showed multivariate splines can be represented as random features in infinitely-wide neural networks with a homogeneous activation function.
result The function space of multivariate splines is a Sobolev space on a Euclidean ball with explicit norm bounds on derivatives.
Develops a diagnostic framework for interest rate model calibration, showing equivalence to Weighted Least Squares and revealing boundary-dominated leverage and local parameter instability.
problem Calibration of stochastic interest rate models
method Diagnostic framework using non-linear regression and analytical tractability of At-The-Money caps
result Reveals boundary-dominated leverage and local parameter instability
We introduce single-set spectral sparsification as a deterministic sampling based feature selection technique for regularized least squares classification, which is the classification analogue to ridge regression. The method is unsupervised and gives worst-case guarantees of the generalization power of the classificati…
Gradient-free method solves infinite-dimensional optimization problems.
problem Optimizing functions in infinite-dimensional spaces.
method Uses directional derivatives and a pre-basis for Hilbert space.
result Proves convergence for solving PDEs using PINNs.
Algorithm leverages low-rank relations between surrogate tasks for structured prediction.
problem Structured prediction with large or infinite-dimensional surrogate spaces.
method Trace norm regularization to leverage relationships between surrogate outputs without explicit coding/decoding functions.
result Our algorithm can improve generalization performance over previous methods.
Boosts Q-learning by using value function bounds.
problem Efficiently solving new tasks using past experience.
method Derives double-sided bounds on optimal value function and uses them to update Q-function.
result Boosted training performance through alternative Q-function update method.
A new method for nonparametric regression using mesh-based solutions.
problem Estimating regression functions non-parametrically with computational tractability.
method Mesh-based approximate solution (MBS) for penalized regression problems.
result MBS transforms NPR to a discrete convex minimization problem, making it computationally feasible.
Leveraged ETFs can boost returns but increase risk.
problem Risk and return trade-off in leveraged ETF investing.
method Bootstrapped Monte-Carlo simulations of mixed stock and bond portfolios.
result Leverage can amplify returns without significantly increasing risk for long-term investors.
Dual optimization connects ERM-fDR to normalization function.
problem Empirical risk minimization with f-divergence regularization.
method Dual formulation, Legendre-Fenchel transform, implicit function theorem, nonlinear ODE.
result Computational method to calculate normalization function efficiently.