Not found
Publikationen
Marcus Schiedung, Axel Don, Michael H Beare, Samuel Abiven (2023). Soil carbon losses due to priming moderated by adaptation and legacy effects. Nature Geoscience, 16(10):1-6. [zora]
Nicholas O E Ofiti, Michael W I Schmidt, Samuel Abiven, Paul J Hanson, Colleen M Iversen, Rachel M Wilson, Joel E Kostka, Guido L B Wiesenberg, Avni Malhotra (2023). Climate warming and elevated CO2 alter peatland soil carbon sources and stability. Nature Communications, 14(1):7533. [zora]
Alessandro Vindigni, Massimo Lopes (2017). Combining electron microscopy with single molecule DNA fiber approaches to study DNA replication dynamics. Biophysical Chemistry, 225:3-9. [zora]
D. Pescia, A. Vindigni (2024). On the spontaneous magnetization of two-dimensional ferromagnets. Ferromagnetism is typically discussed in terms of the exchange interaction and magnetic anisotropies. Yet real samples are inevitably affected by the magnetostatic dipole-dipole interaction. Because of this interaction, a theorem (R.B. Griffiths, Free Energy of interacting magnetic dipoles, Phys. Rev. 176, 655 (1968)) forbids a spontaneous magnetization in, nota bene, three-dimensional bodies. Here we discuss perpendicularly and in-plane magnetized ferromagnetic bodies in the shape of a slab of finite thickness. In perpendicularly magnetized slabs, magnetic domains are energetically favored when the lateral size is sufficiently large, i.e. there is no spontaneous magnetization. For in-plane magnetization, instead, spontaneous magnetization is possible below a critical thickness which, in real thin films, could be as small as few monolayers. At this critical thickness, we predict a genuine phase transition to a multi-domain state. These results have implications for two-dimensional ferromagnetism.. 10.4279/pip.160001 [arxiv] [pdf]
N. Saratz, D. A. Zanin, U. Ramsperger, S. A. Cannas, D. Pescia, A. Vindigni (2014). Critical exponents and scaling invariance in the absence of a critical point. The paramagnetic-to-ferromagnetic phase transition is believed to proceed through a critical point, at which power laws and scaling invariance, associated with the existence of one diverging characteristic length scale -- the so called correlation length -- appear. We indeed observe power laws and scaling behavior over extraordinarily many decades of the suitable scaling variables at the paramagnetic-to-ferromagnetic phase transition in ultrathin Fe films. However, we find that, when the putative critical point is approached, the singular behavior of thermodynamic quantities transforms into an analytic one: the critical point does not exist, it is replaced by a more complex phase involving domains of opposite magnetization, below as well as $above$ the putative critical temperature. All essential experimental results are reproduced by Monte-Carlo simulations in which, alongside the familiar exchange coupling, the competing dipole-dipole interaction is taken into account. Our results imply that a scaling behavior of macroscopic thermodynamic quantities is not necessarily a signature for an underlying second-order phase transition and that the paramagnetic-to-ferromagnetic phase transition proceeds, very likely, in the presence of at least two long spatial scales: the correlation length and the size of magnetic domains. [arxiv] [pdf]
Benedikt Grässle, Stefan Sauter (2025). Dirichlet-to-Neumann operator for the Helmholtz problem with general wavenumbers on the n-sphere. (submitted 2025)
Nis-Erik Bohne, Benedikt Grässle, Stefan Sauter (2024). Pressure-improved Scott-Vogelius type elements. Calcolo, Vol. 62, pp. 1126-5434, (2024) link,
Benedikt Grässle, Nis-Erik Bohne, Stefan Sauter (2022). The pressure-wired Stokes element: a mesh-robust version of the Scott-Vogelius element. Numerische Mathematik, online first (Aug. 2024) link,