Martin Wahl

Higher-Order Spectral Perturbation Expansions I: Simple Eigenvalues and Random Perturbations

Martin Wahl

de (code pays fourni par la source)

Detecting marine climate change refugia using “physiological seascapes”

Gil Rilov, Michael T. Burrows, Amanda E. Bates, Rui Seabra et autres

ca, gr, gb, cn, il, de, us (code pays fourni par la source)

Concentration and moment inequalities for sums of independent heavy-tailed random matrices

Moritz Jirak, Stanislav Minsker, Yiqiu Shen, Martin Wahl

Abstract We prove Fuk-Nagaev and Rosenthal-type inequalities for sums of independent random matrices, focusing on the situation when the norms of the matrices possess finite moments of only low orders. Our bounds depend on the “intrinsic” dimensional characteristics such as the effective …

at, us, de (code pays fourni par la source)

On empirical Hodge Laplacians under the manifold hypothesis

Jan-Paul Lerch, Martin Wahl

Given i.i.d. observations uniformly distributed on a closed submanifold of the Euclidean space, we study higher-order generalizations of graph Laplacians, so-called Hodge Laplacians on graphs, as approximations of the Laplace-Beltrami operator on differential forms. Our main result is a high-probability error bound …

Response of native and invasive grazers to global warming: marine heatwaves vs. gradual trends

Simona Noè, Claudia Bommarito, DM Díaz-Morales, Tamar Guy‐Haim et autres

Ecological responses to global warming are likely driven by a combination of gradual warming trends and extreme climate events, which are increasing in frequency and intensity. Specifically, heatwaves may amplify the impact of ongoing warming, and thus affect species’ physiological responses, behaviour …

it, il, de, us (code pays fourni par la source)

Optimal parameter estimation for linear SPDEs from multiple measurements

Randolf Altmeyer, Anton Tiepner, Martin Wahl

The coefficients in a second order parabolic linear stochastic partial differential equation (SPDE) are estimated from multiple spatially localised measurements. Assuming that the spatial resolution tends to zero and the number of measurements is nondecreasing, the rate of convergence for each coefficient …

gb, us, dk, de (code pays fourni par la source)

Responses at various levels of ecological hierarchy indicate acclimation to sequential sublethal heatwaves in a temperate benthic ecosystem

Maysa Ito, Tamar Guy‐Haim, Yvonne Sawall, Markus Franz et autres

Marine heatwaves have caused massive mortality in coastal benthic ecosystems, altering community composition. Here, we aim to understand the effects of single and sequential sublethal heatwaves in a temperate benthic ecosystem, investigating their disturbance on various levels of ecological hierarchy, i.e. individual …

de, il, bm, fi, it (code pays fourni par la source)

Concentration and moment inequalities for sums of independent heavy-tailed random matrices

Moritz Jirak, Stanislav Minsker, Yiqiu Shen, Martin Wahl

We prove Fuk-Nagaev and Rosenthal-type inequalities for sums of independent random matrices, focusing on the situation when the norms of the matrices possess finite moments of only low orders. Our bounds depend on the ``intrinsic'' dimensional characteristics such as the effective rank, …

Quantitative limit theorems and bootstrap approximations for empirical spectral projectors

Moritz Jirak, Martin Wahl

Abstract Given finite i.i.d. samples in a Hilbert space with zero mean and trace-class covariance operator $$\Sigma $$ Σ , the problem of recovering the spectral projectors of $$\Sigma $$ Σ naturally arises in many applications. In this paper, we consider the …

at, de (code pays fourni par la source)

Impact of persistently high sea surface temperatures on the rhizobiomes of Zostera marina in a Baltic Sea benthocosms

Tânia Aires, Catarina Cúcio, Janina Brakel, Florian Weinberger et autres

Persistently high marine temperatures are escalating and threating marine biodiversity. The Baltic Sea, warming faster than other seas, is a good model to study the impact of increasing sea surface temperatures. Zostera marina, a key player in the Baltic ecosystem, faces susceptibility …

pt, nl, de (code pays fourni par la source)

A kernel-based analysis of Laplacian Eigenmaps

Martin Wahl

Given i.i.d. observations uniformly distributed on a closed manifold $\mathcal{M}\subseteq \mathbb{R}^p$, we study the spectral properties of the associated empirical graph Laplacian based on a Gaussian kernel. Our main results are non-asymptotic error bounds, showing that the eigenvalues and eigenspaces of the …

Reallabor Eckernförder Bucht 2030 – the first living lab covering sea, coast and land

Christian Wagner-Ahlfs, Kai Ahrendt, Hermann W. Bange, Kristine Bauer et autres

1.The living lab method (German: “Reallabor”) is a proven tool from sustainability research. Although it offers a lot of potential for application to complex challenges in marine conservation, it has scarcely been used in this context so far. 2.This article presents the …

de, il (code pays fourni par la source)