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20182026
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19 citations · 61 across the 20 of their papers we have counts for

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math.PR2026

Well-posedness and Hurst parameter estimation for fluid equations driven by fractional transport noise

Alexandra Blessing Neamtu, Dan Crisan, Oana Lang

We study a two-dimensional incompressible vorticity equation on the torus driven by transport-type fractional Brownian noise with Hurst parameter . The model capture…

math.PR2025

A mild rough Gronwall Lemma with applications to non-autonomous evolution equations

Alexandra Blessing, Mazyar Ghani Varzaneh, Tim Seitz

We derive a Gronwall type inequality for mild solutions of non-autonomous parabolic rough partial differential equations (RPDEs). This inequality together with an analysis of the C…

math.PR2023

Existence of smooth stable manifolds for a class of parabolic SPDEs with fractional noise

Xiaofang Lin, Alexandra Neamtu, Caibin Zeng

Little seems to be known about the invariant manifolds for stochastic partial differential equations (SPDEs) driven by nonlinear multiplicative noise. Here we contribute to this as…

math.PR2023

Bifurcation theory for SPDEs: finite-time Lyapunov exponents and amplitude equations

Dirk Blömker, Alexandra Neamtu

We consider a stochastic partial differential equation close to bifurcation of pitchfork type, where a one-dimensional space changes its stability. For finite-time Lyapunov exponen…

math.PR2022

Stochastic evolution equations with rough boundary noise

Alexandra Neamtu, Tim Seitz

We investigate the pathwise well-posedness of stochastic evolution equations perturbed by multiplicative Neumann boundary noise, such as fractional Brownian motion for $H\in(1/3,1/…

math.PR2022★ 1 cited

Quasilinear rough evolution equations

Antoine Hocquet, Alexandra Neamţu

We investigate the abstract Cauchy problem for a quasilinear parabolic equation in a Banach space of the form \( du_t -L_t(u_t)u_t dt = N_t(u_t)dt + F(u_t)\cdot d\mathbf X_t \), wh…

math.PR2021

Center Manifolds for Rough Partial Differential Equations

Christian Kuehn, Alexandra Neamtu

We prove a center manifold theorem for rough partial differential equations (rough PDEs). The class of rough PDEs we consider contains as a key subclass reaction-diffusion equation…

math.PR2021

Amplitude equations for SPDEs driven by fractional additive noise with small Hurst parameter

Dirk Blömker, Alexandra Neamtu

We study stochastic partial differential equations (SPDEs) with potentially very rough fractional noise with Hurst parameter . Close to a change of stability measured wi…

math.PR2021★ 11 cited

On the pitchfork bifurcation for the Chafee-Infante equation with additive noise

Alex Blumenthal, Maximilian Engel, Alexandra Neamtu

We investigate pitchfork bifurcations for a stochastic reaction diffusion equation perturbed by an infinite-dimensional Wiener process. It is well-known that the random attractor i…

math.PR2021

Global solutions for semilinear rough partial differential equations

Robert Hesse, Alexandra Neamtu

We construct global-in-time solutions for semilinear parabolic rough partial differential equations. We work on a scale of Banach spaces tailored to the controlled rough path appro…

math.PR2020

On the equivalence of pathwise mild and weak solutions for quasilinear SPDEs

Gaurav Dhariwal, Florian Huber, Alexandra Neamţu

The main goal of this work is to relate weak and pathwise mild solutions for parabolic quasilinear stochastic partial differential equations (SPDEs). Extending in a suitable way te…

math.PR2020

Random attractors via pathwise mild solutions for stochastic parabolic evolution equations

Christian Kuehn, Alexandra Neamtu, Stefanie Sonner

We investigate the longtime behavior of stochastic partial differential equations (SPDEs) with differential operators that depend on time and the underlying probability space. In p…

math.PR2019

Global martingale solutions for quasilinear SPDEs via the boundedness-by-entropy method

Gaurav Dhariwal, Florian Huber, Ansgar Jüngel +2

The existence of global-in-time bounded martingale solutions to a general class of cross-diffusion systems with multiplicative Stratonovich noise is proved. The equations describe…

math.PR2019

Dynamics of Stochastic Reaction-Diffusion Equations

Christian Kuehn, Alexandra Neamtu

Stochastic partial differential equations (SPDEs) represent a very active research field with numerous recent developments and breakthrough results. There are several well-establis…

math.PR2019

Random Attractors for Stochastic Partly Dissipative Systems

Christian Kuehn, Alexandra Neamtu, Anne Pein

We prove the existence of a global random attractor for a certain class of stochastic partly dissipative systems. These systems consist of a partial (PDE) and an ordinary different…

math.PR2019★ 11 cited

Sample Paths Estimates for Stochastic Fast-Slow Systems driven by Fractional Brownian Motion

Katharina Eichinger, Christian Kuehn, Alexandra Neamtu

We analyze the effect of additive fractional noise with Hurst parameter on fast-slow systems. Our strategy is based on sample paths estimates, similar to the appr…

math.PR2018★ 4 cited

Rough center manifolds

Christian Kuehn, Alexandra Neamtu

Since the breakthrough in rough paths theory for stochastic ordinary differential equations (SDEs), there has been a strong interest in investigating the rough differential equatio…

math.PR2018

Global solutions and random dynamical systems for rough evolution equations

Robert Hesse, Alexandra Neamtu

We consider infinite-dimensional parabolic rough evolution equations. Using regularizing properties of analytic semigroups we prove global-in-time existence of solutions and invest…

math.PR2018

Local mild solutions for rough stochastic partial differential equations

Robert Hesse, Alexandra Neamtu

We investigate mild solutions for stochastic evolution equations driven by a fractional Brownian motion (fBm) with Hurst parameter H in (1/3, 1/2] in infinite-dimensional Banach sp…

math.PR2018

Pathwise mild solutions for quasilinear stochastic partial differential equations

Christian Kuehn, Alexandra Neamtu

Stochastic partial differential equations (SPDEs) have become a key modelling tool in applications. Yet, there are many classes of SPDEs, where the existence and regularity theory…