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

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

Transference Principles for Semigroups and a Theorem of Peller

A general approach to transference principles for discrete and continuous operator (semi)groups is described. This allows to recover the classical transference results of Calder\'on, Coifman and Weiss and of Berkson, Gillespie and Muhly and the more recent one of the author. The method is applied to derive a new transference principle for (discrete and continuous) operator semigroups that need not be groups. As an application, functional calculus estimates for bounded operators with at most polynomially growing powers are derived, culminating in a new proof of classical results by Peller from 1982. The method allows a generalization of his results away from Hilbert spaces to \Ell{p}-spaces and --- involving the concept of $\gamma$-boundedness --- to general Banach spaces. Analogous results for strongly-continuous one-parameter (semi)groups are presented as well. Finally, an application is given to singular integrals for one-parameter semigroups

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

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

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

Shin, Cin, and Jinn in far east Asian, central east Asian, and middle eastern cultures : case studies in transethnic communication by exchange of terminology for elementary spiritual concepts of ethic groups

Methodology and Objects: Methodologically, from a diachronic linguistics perspective regarding the concept of the shin, spirits in folk belief in China and neighbouring cultures, we compare texts that comprise meanings a) historically in the local language and b) compared to the meanings of equivalent terms in languages of other cultures. Comparing sources of this belief, we examine if and how the shin belief can serve as an example of communication across cultural borders including practical forms of worshipping. Argumentation: We argue that the concept of the shin is across cultural and national borders a result from folk culture transcending political or cultural borders transmitted via migration of ethnic groups. Although similar, mind concepts of different cultures and groups never melted; evidence for this independence gives the Islamic distinctive separation between shin and jinn in this area in the Chinese Quran and other spiritual Chinese writings. On the other hand, the practice of worshipping is similar. Conclusions: A spiritual concept like shin varies in practice in different areas. Central Asia as the melting pot of Chinese and Middle East culture shows the cultural practice of Shamanism with shin belief, complex mind concepts like in Daoism, and religions incorporating shin belief (Islam). Observed changes in the particular local languages show the continuity of the local set of meanings. Multilingual and multicultural areas such as Central Asia rather integrate new words to increase their thesaurus with new meanings than to change the set of previous existing meanings in the languages. Arabic as a language of conquerors in Central Asia is a typical example for such a language that serves as a tool to set up new meanings