A transference principle for general groups and functional calculus on UMD spaces

We prove a transference principle for general (i.e., not necessarily bounded) strongly continuous groups on Banach spaces. If the Banach space has the UMD property, the transference principle leads to estimates for the functional calculus of the group generator. In the Hilbert space case, the results cover classical theorems of McIntosh and Boyadzhiev-de Laubenfels; in the UMD case they are analogues of classical results by Hieber and Pruess. By using functional calculus methods, consequences for sectorial operators are derived. For instance it is proved, that every generator of a cosine function on a UMD space has bounded H-infinity calculus on sectors.Comment: 17 pages, no figures. To be published in Mathematische Annale

The group reduction for bounded cosine functions on UMD spaces

It is shown that if A generates a bounded cosine operator function on a UMD space X, then i(-A)^{1/2} generates a bounded C_0-group. The proof uses a transference principle for cosine functions.Comment: 16 pages, research articl

Form Inequalities for Symmetric Contraction Semigroups

Consider --- for the generator ${-}A$ of a symmetric contraction semigroup over some measure space $\mathrm{X}$, $1\le p < \infty$, $q$ the dual exponent and given measurable functions $F_j,\: G_j : \mathbb{C}^d \to \mathbb{C}$ --- the statement: $$\mathrm{Re}\, \sum_{j=1}^m \int_{\mathrm{X}} A F_j(\mathbf{f}) \cdot G_j(\mathbf{f}) \,\,\ge \,\,0$$ {\em for all $\mathbb{C}^d$-valued measurable functions $\mathbf{f}$ on $\mathrm{X}$ such that $F_j(\mathbf{f}) \in \mathrm{dom}(A_p)$ and $G_j(\mathbf{f}) \in \mathrm{L}^q(\mathrm{X})$ for all $j$.} It is shown that this statement is valid in general if it is valid for $\mathrm{X}$ being a two-point Bernoulli $(\frac{1}{2}, \frac{1}{2})$-space and $A$ being of a special form. As a consequence we obtain a new proof for the optimal angle of $\mathrm{L}^{p}$-analyticity for such semigroups, which is essentially the same as in the well-known sub-Markovian case. The proof of the main theorem is a combination of well-known reduction techniques and some representation results about operators on $\mathrm{C}(K)$-spaces. One focus of the paper lies on presenting these auxiliary techniques and results in great detail.Comment: 29 pages; submitted to: Proceedings of the IWOTA, Amsterdam, July 2014. For this updated version, the term "complete contraction" has been exchanged for "absolute contraction" in order to avoid confusion with terminology used in operator space theory. Some small misprints and errors have been corrected, and a reference has been added. The proof of Theorem 4.11 was incomplete and has been amende

Evaluation of \u3ci\u3ePaederus Littorarius\u3c/i\u3e (Coleoptera: Staphylinidae) as an Egg Predator of \u3ci\u3eChrysoteuchia Topiaria\u3c/i\u3e (Lepidoptera: Pyralidae in Wisconsin Cranberry Bogs

A preliminary study was conducted to determine if the rove beetle, Paederus littorarius Grav., would exhibit a feeding preference for the eggs of the pyralid moth, Chrysoteuchia topiaria Zeller, a pest in Wisconsin cran­berry bogs. Individuals were offered a choice of C. topiaria eggs or Drosophila sp. adults for four days. Total number of prey items eaten was converted to weight using a multiplier based on the mean weight of 20 individuals of each prey item, respectively. A significant preference for Drosophila adults was observed in the preference trial; however as many as 24 C. topiaria eggs in addition to Drosophila offerings were consumed by P. littorarius individuals within a 24 h period. Additionally, laboratory and field observations suggests P. littorarius is a polyphagous predator

Two-component electron fluid in underdoped high-TcT_c cuprate superconductors

Evidence from NMR of a two-component spin system in cuprate high-$T_c$ superconductors is shown to be paralleled by similar evidence from the electronic entropy so that a two-component quasiparticle fluid is implicated. We propose that this two-component scenario is restricted to the optimal and underdoped regimes and arises from the upper and lower branches of the reconstructed energy-momentum dispersion proposed by Yang, Rice and Zhang (YRZ) to describe the pseudogap. We calculate the spin susceptibility within the YRZ formalism and show that the doping and temperature dependence reproduces the experimental data for the cuprates.Comment: 5 pages, 2 figures, accepted for publication in European Physics Letter