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Variational Bayesian phylogenetic inference (VBPI) provides a promising general variational framework for efficient estimation of phylogenetic posteriors. However, the current diagonal Lognormal branch length approximation would…

Populations and Evolution · Quantitative Biology 2020-12-02 Cheng Zhang

We characterise the learning of a mixture of two clouds of data points with generic centroids via empirical risk minimisation in the high dimensional regime, under the assumptions of generic convex loss and convex regularisation. Each cloud…

Machine Learning · Statistics 2024-03-19 Urte Adomaityte , Gabriele Sicuro , Pierpaolo Vivo

This paper proposes a semiparametric joint VaRES framework driven by realized information, mo tivated by the economic mechanisms underlying tail risk generation. Building on the CAViaR quantile recursion, the model introduces a dynamic…

General Economics · Economics 2026-01-06 Sicheng Fu

The real-world data distribution is essentially long-tailed, which poses great challenge to the deep model. In this work, we propose a new method, Gradual Balanced Loss and Adaptive Feature Generator (GLAG) to alleviate imbalance. GLAG…

Computer Vision and Pattern Recognition · Computer Science 2022-03-02 Zihan Zhang , Xiang Xiang

We extend the L\'evy Langevin Monte Carlo method studied by Oechsler in 2024 to the setting of a target distribution with heavy tails: Choosing a target distribution from the class of subexponential distributions we prove convergence of a…

Probability · Mathematics 2025-07-15 Anita Behme , Claudius Lütke Schwienhorst

We establish a large deviation principle for the normalized excursion and bridge of an $\alpha$-stable L\'evy process without negative jumps, with $1<\alpha<2$. Based on this, we derive precise asymptotics for the tail distributions of…

Probability · Mathematics 2024-12-05 Léo Dort , Christina Goldschmidt , Grégory Miermont

Normalizing Flows (NFs) have been established as a principled framework for generative modeling. Standard NFs consist of a forward process and a reverse process: the forward process maps data to noise, while the reverse process generates…

Machine Learning · Computer Science 2025-12-12 Yiyang Lu , Qiao Sun , Xianbang Wang , Zhicheng Jiang , Hanhong Zhao , Kaiming He

Imitation learning algorithms learn viable policies by imitating an expert's behavior when reward signals are not available. Generative Adversarial Imitation Learning (GAIL) is a state-of-the-art algorithm for learning policies when the…

The framework of normalizing flows provides a general strategy for flexible variational inference of posteriors over latent variables. We propose a new type of normalizing flow, inverse autoregressive flow (IAF), that, in contrast to…

Machine Learning · Computer Science 2017-02-01 Diederik P. Kingma , Tim Salimans , Rafal Jozefowicz , Xi Chen , Ilya Sutskever , Max Welling

We study a Monte Carlo algorithm for simulation of probability distributions based on stochastic step functions, and compare to the traditional Metropolis/Hastings method. Unlike the latter, the step function algorithm can produce an…

Probability · Mathematics 2015-12-07 Torquil Macdonald Sørensen , Fred Espen Benth

Stochastic linear modelling proposed in Tissot, M\'emin & Cavalieri (J. Fluid Mech., vol. 912, 2021, A51) is based on classical conservation laws subject to a stochastic transport. Once linearised around the mean flow and expressed in the…

Fluid Dynamics · Physics 2022-07-27 Gilles Tissot , André Cavalieri , Etienne Mémin

We present a computational framework for efficient learning, sampling, and distribution of general Bayesian posterior distributions. The framework leverages a machine learning approach for the construction of normalizing flows for the…

Nuclear Theory · Physics 2023-10-10 Yukari Yamauchi , Landon Buskirk , Pablo Giuliani , Kyle Godbey

This paper presents a novel approach to stochastic volatility (SV) modeling by utilizing nonparametric techniques that enhance our ability to capture the volatility of financial time series data, with a particular emphasis on the…

Computation · Statistics 2025-02-18 Yudong Feng , Ashis Gangopadhyay

Normalizing Flows are generative models that directly maximize the likelihood. Previously, the design of normalizing flows was largely constrained by the need for analytical invertibility. We overcome this constraint by a training procedure…

Machine Learning · Computer Science 2024-04-25 Felix Draxler , Peter Sorrenson , Lea Zimmermann , Armand Rousselot , Ullrich Köthe

We show how to reduce the problem of computing VaR and CVaR with Student T return distributions to evaluation of analytical functions of the moments. This allows an analysis of the risk properties of systems to be carefully attributed…

Portfolio Management · Quantitative Finance 2011-03-01 William T. Shaw

We consider a class of assets whose risk-neutral pricing dynamics are described by an exponential L\'evy-type process subject to default. The class of processes we consider features locally-dependent drift, diffusion and default-intensity…

Computational Finance · Quantitative Finance 2013-04-19 Antoine Jacquier , Matthew Lorig

The L\'evy-stable distribution is the attractor of distributions which hold power laws with infinite variance. This distribution has been used in a variety of research areas, for example in economics it is used to model financial market…

Statistical Mechanics · Physics 2018-07-11 Karina Arias-Calluari , Fernando Alonso-Marroquin , Michael Harre

Recently, extracting data-driven governing laws of dynamical systems through deep learning frameworks has gained a lot of attention in various fields. Moreover, a growing amount of research work tends to transfer deterministic dynamical…

Machine Learning · Statistics 2022-07-05 Cheng Fang , Yubin Lu , Ting Gao , Jinqiao Duan

We consider stochastic control systems affected by a fast mean reverting volatility $Y(t)$ driven by a pure jump L\'evy process. Motivated by a large literature on financial models, we assume that $Y(t)$ evolves at a faster time scale…

Probability · Mathematics 2014-05-27 Martino Bardi , Annalisa Cesaroni , Andrea Scotti

We show that the quotient of Levy processes of jump-diffusion type has a fat-tailed distribution. An application is to price theory in economics. We show that fat tails arise endogenously from modeling of price change based on an excess…

General Economics · Economics 2021-03-11 Gunduz Caginalp