40,823 research outputs found
Diophantine approximation on Veech surfaces
We show that Y. Cheung's general -continued fractions can be adapted to
give approximation by saddle connection vectors for any compact translation
surface. That is, we show the finiteness of his Minkowski constant for any
compact translation surface. Furthermore, we show that for a Veech surface in
standard form, each component of any saddle connection vector dominates its
conjugates. The saddle connection continued fractions then allow one to
recognize certain transcendental directions by their developments
Current Correlations in Quantum Spin Hall Insulators
We consider a four-terminal setup of a two-dimensional topological insulator
(quantum spin Hall insulator) with local tunneling between the upper and lower
edges. The edge modes are modeled as helical Luttinger liquids and the
electron-electron interactions are taken into account exactly. Using
perturbation theory in the tunneling, we derive the cumulant generating
function for the inter-edge current. We show that different possible transport
channels give rise to different signatures in the current noise and current
cross-correlations, which could be exploited in experiments to elucidate the
interplay between electron-electron interactions and the helical nature of the
edge states.Comment: 5 pages, 2 figure
Tame Class Field Theory for Singular Varieties over Finite Fields
Schmidt and Spie{\ss} described the abelian tame fundamental group of a
smooth variety over a finite field by using Suslin homology. In this paper we
show that their result generalizes to singular varieties if one uses
Weil-Suslin homology instead.Comment: some typos corrected, to appear in Journal EM
Immunotherapy of invasive fungal infection in hematopoietic stem cell transplant recipients
Despite the availability of new antifungal compounds, invasive fungal infection remains a significant cause of morbidity and mortality in children and adults undergoing allogeneic hematopoietic stem cell transplantation (HSCT). Allogeneic HSCT recipients suffer from a long lasting defect of different arms of the immune system, which increases the risk for and deteriorates the prognosis of invasive fungal infections. In turn, advances in understanding these immune deficits have resulted in promising strategies to enhance or restore critical immune functions in allogeneic HSCT recipients. Potential approaches include the administration of granulocytes, since neutropenia is the single most important risk factor for invasive fungal infection, and preliminary clinical results suggest a benefit of adoptively transferred donor-derived antifungal T cells. In vitro data and animal studies demonstrate an antifungal effect of natural killer cells, but clinical data are lacking to date. This review summarizes and critically discusses the available data of immunotherapeutic strategies in allogeneic HSCT recipients suffering from invasive fungal infection
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