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20062026
most citedExact and high order discretization schemes for Wishart processes and their affine extensions

36 citations · 126 across the 37 of their papers we have counts for

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math.PR2026

Ergodic approximation for the invariant distribution: An abstract framework for law-dependent dynamics

Aurélien Alfonsi, Vlad Bally, Lucia Caramellino +1

This paper studies the approximation of invariant distributions for a broad class of law-dependent dynamics, including McKean-Vlasov stochastic differential equations and Boltzmann…

math.PR2026

Weak error approximation for rough and Gaussian mean-reverting stochastic volatility models

Aurélien Alfonsi, Ahmed Kebaier

For a class of stochastic models with Gaussian and rough mean-reverting volatility that embeds the genuine rough Stein-Stein model, we study the weak approximation rate when using…

math.PR2025

Euler-type approximation for the invariant measure: An abstract framework

Aurélien Alfonsi, Vlad Bally, Arturo Kohatsu-Higa

We establish a general framework to study the rate of convergence of a Euler type approximation scheme with decreasing time steps to the invariant measure, for a general class of s…

math.PR2025

Wasserstein projections in the convex order: regularity and characterization in the quadratic Gaussian case

Aurélien Alfonsi, Benjamin Jourdain

In this paper, we first show continuity of both Wasserstein projections in the convex order when they are unique. We also check that, in arbitrary dimension , the quadratic Wass…

math.PR2025

Quadratic Wasserstein distance between Gaussian laws revisited with correlation

Aurélien Alfonsi, Benjamin Jourdain

In this note, we give a simple derivation of the formula obtained in Dowson and Landau (1982), Olkin and Pukelsheim (1982) and Givens and Shortt (1984) for the quadratic Wasserstei…

math.PR2025

Weak solutions of Stochastic Volterra Equations in convex domains with general kernels

Eduardo Abi Jaber, Aurélien Alfonsi, Guillaume Szulda

We establish new weak existence results for -dimensional Stochastic Volterra Equations (SVEs) with continuous coefficients and possibly singular one-dimensional non-convolution…

math.PR2024★ 1 cited

On non-negative solutions of stochastic Volterra equations with jumps and non-Lipschitz coefficients

Aurélien Alfonsi, Guillaume Szulda

We consider one-dimensional stochastic Volterra equations with jumps for which we establish conditions upon the convolution kernel and coefficients for the strong existence and pat…

math.PR2023★ 1 cited

Nonnegativity preserving convolution kernels. Application to Stochastic Volterra Equations in closed convex domains and their approximation

Aurélien Alfonsi

This work defines and studies one-dimensional convolution kernels that preserve nonnegativity. When the past dynamics of a process is integrated with a convolution kernel like in S…

math.PR2021★ 1 cited

Construction of Boltzmann and McKean Vlasov type flows (the sewing lemma approach)

Aurélien Alfonsi, Vlad Bally

We are concerned with a mixture of Boltzmann and McKean-Vlasov type equations, this means (in probabilistic terms) equations with coefficients depending on the law of the solution…

math.PR2021★ 7 cited

Approximation of Stochastic Volterra Equations with kernels of completely monotone type

Aurélien Alfonsi, Ahmed Kebaier

In this work, we develop a multifactor approximation for -dimensional Stochastic Volterra Equations (SVE) with Lipschitz coefficients and kernels of completely monotone type tha…

math.PR2019

A generic construction for high order approximation schemes of semigroups using random grids

Aurélien Alfonsi, Vlad Bally

Our aim is to construct high order approximation schemes for general semigroups of linear operators . In order to do it, we fix a time horizon and the discretiz…

math.PR2019★ 15 cited

Approximation of Optimal Transport problems with marginal moments constraints

Aurélien Alfonsi, Rafaël Coyaud, Virginie Ehrlacher +1

Optimal Transport (OT) problems arise in a wide range of applications, from physics to economics. Getting numerical approximate solution of these problems is a challenging issue of…

math.PR2018★ 11 cited

Squared quadratic Wasserstein distance : optimal couplings and Lions differentiability

Aurélien Alfonsi, Benjamin Jourdain

In this paper, we remark that any optimal coupling for the quadratic Wasserstein distance between two probability measures and with finite second order moments…

math.PR2017★ 3 cited

Sampling of probability measures in the convex order by Wasserstein projection

Aurélien Alfonsi, Jacopo Corbetta, Benjamin Jourdain

In this paper, for and two probability measures on with finite moments of order , we define the respective projections for the -Wasserstein dist…

math.PR2016

Evolution of the Wasserstein distance between the marginals of two Markov processes

Aurélien Alfonsi, Jacopo Corbetta, Benjamin Jourdain

In this paper, we are interested in the time derivative of the Wasserstein distance between the marginals of two Markov processes. As recalled in the introduction, the Kantorovich…

math.PR2014★ 2 cited

Optimal transport bounds between the time-marginals of a multidimensional diffusion and its Euler scheme

Aurélien Alfonsi, Benjamin Jourdain, Arturo Kohatsu-Higa

In this paper, we prove that the time supremum of the Wasserstein distance between the time-marginals of a uniformly elliptic multidimensional diffusion with coefficients bounded t…

math.PR2013

A remark on the optimal transport between two probability measures sharing the same copula

Aurélien Alfonsi, Benjamin Jourdain

We are interested in the Wasserstein distance between two probability measures on sharing the same copula . The image of the probability measure by the vectors of ps…

math.PR2013★ 5 cited

Stochastic Local Intensity Loss Models with Interacting Particle Systems

Aurélien Alfonsi, Céline Labart, Jérôme Lelong

It is well-known from the work of Schönbucher (2005) that the marginal laws of a loss process can be matched by a unit increasing time inhomogeneous Markov process, whose determini…

math.PR2012★ 28 cited

Pathwise optimal transport bounds between a one-dimensional diffusion and its Euler scheme

A. Alfonsi, B. Jourdain, A. Kohatsu-Higa

In the present paper, we prove that the Wasserstein distance on the space of continuous sample-paths equipped with the supremum norm between the laws of a uniformly elliptic one-di…

math.PR2012★ 2 cited

Strong convergence of some drift implicit Euler scheme. Application to the CIR process

Aurélien Alfonsi

We study the convergence of a drift implicit scheme for one-dimensional SDEs that was considered by Alfonsi for the Cox-Ingersoll-Ross (CIR) process. Under general conditions, we o…

math.PR2011

A Mean-Reverting SDE on Correlation matrices

Abdelkoddousse Ahdida, Aurélien Alfonsi

We introduce a mean-reverting SDE whose solution is naturally defined on the space of correlation matrices. This SDE can be seen as an extension of the well-known Wright-Fisher dif…

math.PR2010★ 36 cited

Exact and high order discretization schemes for Wishart processes and their affine extensions

Abdelkoddousse Ahdida, Aurélien Alfonsi

This work deals with the simulation of Wishart processes and affine diffusions on positive semidefinite matrices. To do so, we focus on the splitting of the infinitesimal generator…

math.PR2006★ 1 cited

General Duality for Perpetual American Options

Aurélien Alfonsi, Benjamin Jourdain

In this paper, we investigate the generalization of the Call-Put duality equality obtained in [1] for perpetual American options when the Call-Put payoff is replaced by $…

math.PR2006★ 2 cited

A Call-Put Duality for Perpetual American Options

Aurélien Alfonsi, Benjamin Jourdain

It is well known that in models with time-homogeneous local volatility functions and constant interest and dividend rates, the European Put prices are transformed into European Cal…