{"title":"On Riemann–Liouville type operators, bounded mean oscillation, gradient estimates and approximation on the Wiener space","authors":"Stefan Geiss , Nguyen Tran Thuan","doi":"10.1016/j.spa.2025.104651","DOIUrl":"10.1016/j.spa.2025.104651","url":null,"abstract":"<div><div>We discuss in a stochastic framework the interplay between Riemann–Liouville type operators applied to stochastic processes, bounded mean oscillation, real interpolation, and approximation. In particular, we investigate the singularity of gradient processes on the Wiener space arising from parabolic PDEs via the Feynman–Kac theory. The singularity is measured in terms of bmo-conditions on the fractional integrated gradient. As an application we treat an approximation problem for stochastic integrals on the Wiener space. In particular, we provide a discrete time hedging strategy for the binary option with a uniform local control of the hedging error under a shortfall constraint.</div></div>","PeriodicalId":51160,"journal":{"name":"Stochastic Processes and their Applications","volume":"187 ","pages":"Article 104651"},"PeriodicalIF":1.1,"publicationDate":"2025-04-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143843569","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Strang splitting for parametric inference in second-order stochastic differential equations","authors":"Predrag Pilipovic , Adeline Samson , Susanne Ditlevsen","doi":"10.1016/j.spa.2025.104650","DOIUrl":"10.1016/j.spa.2025.104650","url":null,"abstract":"<div><div>We address parameter estimation in second-order stochastic differential equations (SDEs), which are prevalent in physics, biology, and ecology. The second-order SDE is converted to a first-order system by introducing an auxiliary velocity variable, which raises two main challenges. First, the system is hypoelliptic since the noise affects only the velocity, making the Euler–Maruyama estimator ill-conditioned. We propose an estimator based on the Strang splitting scheme to overcome this. Second, since the velocity is rarely observed, we adapt the estimator to partial observations. We present four estimators for complete and partial observations, using the full pseudo-likelihood or only the velocity-based partial pseudo-likelihood. These estimators are intuitive, easy to implement, and computationally fast, and we prove their consistency and asymptotic normality. Our analysis demonstrates that using the full pseudo-likelihood with complete observations reduces the asymptotic variance of the diffusion estimator. With partial observations, the asymptotic variance increases as a result of information loss but remains unaffected by the likelihood choice. However, a numerical study on the Kramers oscillator reveals that using the partial pseudo-likelihood for partial observations yields less biased estimators. We apply our approach to paleoclimate data from the Greenland ice core by fitting the Kramers oscillator model, capturing transitions between metastable states reflecting observed climatic conditions during glacial eras.</div></div>","PeriodicalId":51160,"journal":{"name":"Stochastic Processes and their Applications","volume":"187 ","pages":"Article 104650"},"PeriodicalIF":1.1,"publicationDate":"2025-04-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143829599","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Ancestral lineages for a branching annihilating random walk","authors":"Pascal Oswald","doi":"10.1016/j.spa.2025.104648","DOIUrl":"10.1016/j.spa.2025.104648","url":null,"abstract":"<div><div>We study the ancestral lineages of individuals of a stationary discrete-time branching annihilating random walk (BARW) on the <span><math><mi>d</mi></math></span>-dimensional lattice <span><math><msup><mrow><mi>Z</mi></mrow><mrow><mi>d</mi></mrow></msup></math></span>. Each individual produces a Poissonian number of offspring with mean <span><math><mi>μ</mi></math></span> which then jump independently to a uniformly chosen site with a fixed distance <span><math><mi>R</mi></math></span> of their parent. Should two or more particles jump to the same site, all particles at that site get annihilated. By interpreting the ancestral lineage of such an individual as a random walk in a dynamical random environment, we obtain a law of large numbers and a functional central limit theorem for the ancestral lineage whenever the model parameters satisfy <span><math><mrow><mi>μ</mi><mo>∈</mo><mrow><mo>(</mo><mn>1</mn><mo>,</mo><msup><mrow><mi>e</mi></mrow><mrow><mn>2</mn></mrow></msup><mo>)</mo></mrow></mrow></math></span> and <span><math><mrow><mi>R</mi><mo>=</mo><mi>R</mi><mrow><mo>(</mo><mi>μ</mi><mo>)</mo></mrow></mrow></math></span> is large enough.</div></div>","PeriodicalId":51160,"journal":{"name":"Stochastic Processes and their Applications","volume":"187 ","pages":"Article 104648"},"PeriodicalIF":1.1,"publicationDate":"2025-04-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143835136","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Mario Maurelli , Daniela Morale , Stefania Ugolini
{"title":"Well-posedness of a reaction–diffusion model with stochastic dynamical boundary conditions","authors":"Mario Maurelli , Daniela Morale , Stefania Ugolini","doi":"10.1016/j.spa.2025.104646","DOIUrl":"10.1016/j.spa.2025.104646","url":null,"abstract":"<div><div>We study the well-posedness of a nonlinear reaction diffusion partial differential equation system on the half-line coupled with a stochastic dynamical boundary condition, a random system arising from the description of the chemical reaction of sulphur dioxide with calcium carbonate stones. The boundary condition is given by a Jacobi process, solution to a stochastic differential equation with a mean-reverting drift and a bounded diffusion coefficient. The main result is the global existence and the pathwise uniqueness of mild solutions. The proof relies on a splitting strategy, which allows to deal with the low regularity of the dynamical boundary condition.</div></div>","PeriodicalId":51160,"journal":{"name":"Stochastic Processes and their Applications","volume":"186 ","pages":"Article 104646"},"PeriodicalIF":1.1,"publicationDate":"2025-04-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143808735","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Inference in nonlinear random fields and non-asymptotic rates for threshold variance estimators under sparse dependence","authors":"Ansgar Steland","doi":"10.1016/j.spa.2025.104649","DOIUrl":"10.1016/j.spa.2025.104649","url":null,"abstract":"<div><div>Inference based on the (functional) central limit theorem for nonlinear random fields is studied and generalized to the nonstationary case. For this purpose, nonparametric estimation of the variance of partial sums is studied in depth including a class of soft-thresholding estimators. Nonasymptotic convergence rates for all estimators are established. It is shown that threshold estimation is superior in terms of the convergence rate under a mild sparseness condition on the spatial covariance structure. The results also cover estimators calculated from residuals. Applications to hypothesis testing to detect effects such as tumors in CT images, regression models with external regressors, and sparse convolutional network layers are discussed.</div></div>","PeriodicalId":51160,"journal":{"name":"Stochastic Processes and their Applications","volume":"186 ","pages":"Article 104649"},"PeriodicalIF":1.1,"publicationDate":"2025-04-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143823863","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Long run convergence of discrete-time interacting particle systems of the McKean–Vlasov type","authors":"Pascal Bianchi , Walid Hachem , Victor Priser","doi":"10.1016/j.spa.2025.104647","DOIUrl":"10.1016/j.spa.2025.104647","url":null,"abstract":"<div><div>We consider a discrete-time system of <span><math><mi>n</mi></math></span> coupled random vectors, a.k.a. interacting particles. The dynamics involve a vanishing step size, some random centered perturbations, and a mean vector field which induces the coupling between the particles. We study the doubly asymptotic regime where both the number of iterations and the number <span><math><mi>n</mi></math></span> of particles tend to infinity, without any constraint on the relative rates of convergence of these two parameters. We establish that the empirical measure of the interpolated trajectories of the particles converges in probability, in an ergodic sense, to the set of recurrent McKean–Vlasov distributions. We also consider the pointwise convergence of the empirical measures of the particles. We consider the example of the granular media equation, where the particles are shown to converge to a critical point of the Helmholtz energy.</div></div>","PeriodicalId":51160,"journal":{"name":"Stochastic Processes and their Applications","volume":"186 ","pages":"Article 104647"},"PeriodicalIF":1.1,"publicationDate":"2025-04-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143815876","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Lévy models amenable to efficient calculations","authors":"Svetlana Boyarchenko , Sergei Levendorskiĭ","doi":"10.1016/j.spa.2025.104636","DOIUrl":"10.1016/j.spa.2025.104636","url":null,"abstract":"<div><div>In our previous publications (IJTAF 2019, Math. Finance 2020), we introduced a general class of SINH-regular processes and demonstrated that efficient numerical methods for the evaluation of the Wiener–Hopf factors and various probability distributions (prices of options of several types) in Lévy models can be developed using only a few general properties of the characteristic exponent <span><math><mi>ψ</mi></math></span>. Essentially all popular Lévy processes enjoy these properties. In the present paper, we define classes of Stieltjes–Lévy processes (SL-processes) as processes with completely monotone Lévy densities of positive and negative jumps, and signed Stieltjes–Lévy processes (sSL-processes) as processes with densities representable as differences of completely monotone densities. We demonstrate that (1) all crucial properties of <span><math><mi>ψ</mi></math></span> are consequences of a certain representation of the characteristic exponent in terms of a pair of Stieltjes measures or a pair of differences of two Stieltjes measures (SL- and sSL-processes); (2) essentially all popular processes other than Merton’s model and Meixner processes are SL-processes; (3) Meixner processes are sSL-processes; (4) under a natural symmetry condition, essentially all popular classes of Lévy processes are SL- or sSL-subordinated Brownian motion. We use the properties of (s)SL-processes to derive new formulas for the Wiener–Hopf factors <span><math><msubsup><mrow><mi>ϕ</mi></mrow><mrow><mi>q</mi></mrow><mrow><mo>±</mo></mrow></msubsup></math></span> for small <span><math><mi>q</mi></math></span> in terms of the absolute continuous components of SL-measures and their densities, and calculate the leading terms of the survival probability also in terms of the absolute continuous components of SL-measures and their densities. The lower tail probability is calculated for more general classes of SINH-regular processes.</div></div>","PeriodicalId":51160,"journal":{"name":"Stochastic Processes and their Applications","volume":"186 ","pages":"Article 104636"},"PeriodicalIF":1.1,"publicationDate":"2025-04-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143830195","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Stochastic chemical reaction networks with discontinuous limits and AIMD processes","authors":"Lucie Laurence , Philippe Robert","doi":"10.1016/j.spa.2025.104643","DOIUrl":"10.1016/j.spa.2025.104643","url":null,"abstract":"<div><div>In this paper we study a class of stochastic chemical reaction networks (CRNs) for which chemical species are created by a sequence of chain reactions. We prove that under some convenient conditions on the initial state, some of these networks exhibit a discrete-induced transitions (DIT) property: isolated, random, events have a direct impact on the macroscopic state of the process. Although this phenomenon has already been noticed in several CRNs, in auto-catalytic networks in the literature of physics in particular, there are up to now few rigorous studies in this domain. A scaling analysis of several cases of such CRNs with several classes of initial states is achieved. The DIT property is investigated for the case of a CRN with four nodes. We show that on the normal timescale and for a subset of (large) initial states and for convenient Skorohod topologies, the scaled process converges in distribution to a Markov process with jumps, an Additive Increase/Multiplicative Decrease (AIMD) process. This asymptotically discontinuous limiting behavior is a consequence of a DIT property due to random, local, blowups of jumps occurring during small time intervals. With an explicit representation of invariant measures of AIMD processes and time-change arguments, we show that, with a speed-up of the timescale, the scaled process is converging in distribution to a continuous deterministic function. The DIT property analyzed in this paper is connected to a simple chain reaction between three chemical species and is therefore likely to be a quite generic phenomenon for a large class of CRNs.</div></div>","PeriodicalId":51160,"journal":{"name":"Stochastic Processes and their Applications","volume":"186 ","pages":"Article 104643"},"PeriodicalIF":1.1,"publicationDate":"2025-04-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143777273","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Stationary fluctuations for a multi-species zero range process with long jumps","authors":"Linjie Zhao","doi":"10.1016/j.spa.2025.104645","DOIUrl":"10.1016/j.spa.2025.104645","url":null,"abstract":"<div><div>We consider stationary fluctuations for the multi-species zero range process with long jumps in one dimension, where the underlying transition probability kernel is <span><math><mrow><mi>p</mi><mrow><mo>(</mo><mi>x</mi><mo>)</mo></mrow><mo>=</mo><msub><mrow><mi>c</mi></mrow><mrow><mo>+</mo></mrow></msub><msup><mrow><mrow><mo>|</mo><mi>x</mi><mo>|</mo></mrow></mrow><mrow><mo>−</mo><mn>1</mn><mo>−</mo><mi>α</mi></mrow></msup></mrow></math></span> if <span><math><mrow><mi>x</mi><mo>></mo><mn>0</mn></mrow></math></span> and <span><math><mrow><mo>=</mo><msub><mrow><mi>c</mi></mrow><mrow><mo>−</mo></mrow></msub><msup><mrow><mrow><mo>|</mo><mi>x</mi><mo>|</mo></mrow></mrow><mrow><mo>−</mo><mn>1</mn><mo>−</mo><mi>α</mi></mrow></msup></mrow></math></span> if <span><math><mrow><mi>x</mi><mo><</mo><mn>0</mn></mrow></math></span>. Above, <span><math><mrow><msub><mrow><mi>c</mi></mrow><mrow><mo>±</mo></mrow></msub><mo>≥</mo><mn>0</mn><mo>,</mo><mi>α</mi><mo>></mo><mn>0</mn></mrow></math></span> are parameters. We prove that for <span><math><mrow><mn>0</mn><mo><</mo><mi>α</mi><mo><</mo><mn>3</mn><mo>/</mo><mn>2</mn></mrow></math></span>, the density fluctuation fields converge to the stationary solution of a coupled fractional Ornstein–Uhlenbeck process, and for <span><math><mrow><mi>α</mi><mo>=</mo><mn>3</mn><mo>/</mo><mn>2</mn></mrow></math></span>, the limit points are concentrated on stationary energy solutions of a coupled fractional Burgers equation.</div></div>","PeriodicalId":51160,"journal":{"name":"Stochastic Processes and their Applications","volume":"186 ","pages":"Article 104645"},"PeriodicalIF":1.1,"publicationDate":"2025-04-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143768621","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Andreas E. Kyprianou , Sonny Medina , Juan Carlos Pardo
{"title":"α-stable Lévy processes entering the half space or a slab","authors":"Andreas E. Kyprianou , Sonny Medina , Juan Carlos Pardo","doi":"10.1016/j.spa.2025.104644","DOIUrl":"10.1016/j.spa.2025.104644","url":null,"abstract":"<div><div>Recently a series of publications, including e.g. (Kyprianou, 2016 <span><span>[1]</span></span>; Kyprianou et al., 2018 <span><span>[2]</span></span>; Kyprianou et al., 2019; Kyprianou et al., 2014; Kyprianou and Pardo, 2022), considered a number of new fluctuation identities for <span><math><mi>α</mi></math></span>-stable Lévy processes in one and higher dimensions by appealing to underlying Lamperti-type path decompositions. In the setting of <span><math><mi>d</mi></math></span>-dimensional isotropic processes, (Kyprianou et al., 2019) in particular, developed so called <span><math><mi>n</mi></math></span>-tuple laws for first entrance and exit of balls. Fundamental to these works is the notion that the paths can be decomposed via generalised spherical polar coordinates revealing an underlying Markov Additive Process (MAP) for which a more advanced form of excursion theory (in the sense of Maisonneuve (1975)) can be exploited.</div><div>Inspired by this approach, we give a different decomposition of the <span><math><mi>d</mi></math></span>-dimensional isotropic <span><math><mi>α</mi></math></span>-stable Lévy processes in terms of orthogonal coordinates. Accordingly we are able to develop a number of <span><math><mi>n</mi></math></span>-tuple laws for first entrance into a half-space bounded by an <span><math><msup><mrow><mi>R</mi></mrow><mrow><mi>d</mi><mo>−</mo><mn>1</mn></mrow></msup></math></span> hyperplane, expanding on existing results of (Byczkowski et al., 2009; Tamura and Tanaka, 2008). This gives us the opportunity to numerically construct the law of first entry of the process into a slab of the form <span><math><mrow><mrow><mo>(</mo><mo>−</mo><mn>1</mn><mo>,</mo><mn>1</mn><mo>)</mo></mrow><mo>×</mo><msup><mrow><mi>R</mi></mrow><mrow><mi>d</mi><mo>−</mo><mn>1</mn></mrow></msup></mrow></math></span> using a ‘walk-on-half-spaces’ Monte Carlo approach in the spirit of the ‘walk-on-spheres’ Monte Carlo method given in Kyprianou et al. (2018).</div></div>","PeriodicalId":51160,"journal":{"name":"Stochastic Processes and their Applications","volume":"186 ","pages":"Article 104644"},"PeriodicalIF":1.1,"publicationDate":"2025-03-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143808734","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}