Response functions as quantifiers of non-Markovianity

Quantum non-Markovianity is crucially related to the study of dynamical maps, which are usually derived for initially factorized system-bath states. We here demonstrate that linear response theory also provides a way to derive dynamical maps, but for initially correlated (and in general entangled) states. Importantly, these maps are always time-translational invariant and allow for a much simpler quantification of non-Markovianity compared to previous approaches. We apply our theory to the Caldeira-Leggett model, for which our quantifier is valid beyond linear response and can be expressed analytically. We find that a classical Brownian particle coupled to an Ohmic bath can already exhibit non-Markovian behaviour, a phenomenon related to the initial state preparation procedure. Furthermore, for a peaked spectral density we demonstrate that there is no monotonic relation between our quantifier and the system-bath coupling strength, the sharpness of the peak or the resonance frequency in the bath.Comment: Updated version with additional information. 5 + 5 pages incl. 2 figures. Comments are welcom

Is Truth Relevant? On the Relevance of Relevance

An assertion can be a factual claim or the expression of a value judgment. Since Hume the view that these are two incompatible types of assertions that cannot be connected by argumentation, has often been defended, and, more recently, has also been called into question. In the following paper I attempt to show that the truth both of a descriptive sentence and of a normative sentence is derived from its “practical relevance”. The demand that an assertion must be true and must be based on knowledge of the asserter is derived from the demand that an assertion must be practically relevant to the addressee. On the basis of this claim I will sketch a model of what it m

Anomalies and large N limits in matrix string theory

We study the loop expansion for the low energy effective action for matrix string theory. For long string configurations we find the result depends on the ordering of limits. Taking $g_s\to 0$ before $N\to\infty$ we find free strings. Reversing the order of limits however we find anomalous contributions coming from the large $N$ limit that invalidate the loop expansion. We then embed the classical instanton solution into a long string configuration. We find the instanton has a loop expansion weighted by fractional powers of $N$. Finally we identify the scaling regime for which interacting long string configurations have a well defined large $N$ limit. The limit corresponds to large "classical" strings and can be identified with the "dual of the 't Hooft limit, $g_{SYM}^2\sim N$.Comment: 13 pages, 1 figure, harvmac.tex, notational errors corrected, references added. Trivial error in section 5 corrected with the result that the domain of validity of the loop expn. is slightly modifie

Die Xerothermrasen-Gesellschaften des unteren Unstruttales und einige ökologische Gründe für ihre Verteilung im Raum

Das Gebiet an der unteren Unstrut nimmt hinsichtlich seiner Vegetation und Flora eine Sonderstellung ein, da sich hier kontinental und (sub-)mediterran verbreitete Sippen mischen. In den Xerothermrasen profitieren die östlichen Sippen vom subkontinentalen Klima, während der vorherrschende Muschelkalk-Untergrund und die Sommerwärme die zahlreichen kalkliebenden südlichen Sippen begünstigen. Daneben stellt das Unstruttal ein bedeutsames Refugialgebiet reliktischer Steppen- und Mittelmeerarten dar (BECKER 2000). Alles zusammen bewirkt eine überdurchschnittlich hohe Artenvielfalt und eine hohe Zahl verschiedener Xerothermrasen-Gesellschaften. Diese Gesellschaften und die mikroklimatischen und edaphischen Gründe für ihre Verteilung im Raum zu beschreiben, ist ein Ziel der vorliegenden Arbeit (VGL. BECKER 1996; s.a. BECKER 1998a, b). Kleinere Teilgebiete des Unstruttales wurden hinsichtlich ihrer Xerothermrasen-Gesellschaften bereits untersucht, so das NSG Steinklöbe von MEUSEL (1937) sowie HÖLZEL (1997), das NSG Neue Göhle von ALTEHAGE (1951) und das NSG Tote Täler von REICHHOFF et al. (1979). Auch bei KRAUSE (1940) finden sich interessante Überlegungen zu einzelnen Arten, während HENSEN (1997), BÖTTNER et al. (1997), HENSEN & KENTRUP (1998) und HEINZ & PFEIFFER (1998) mehrere Gesellschaften im Gebiet hinsichtlich der Lebensstrategien ihrer Arten untersucht haben. Schließlich sei noch die Studie von MAHN (1965) genannt, mit der man die pflanzensoziologischen Ergebnisse in einen größeren Kontext stellen kann. Mit der Rolle von Mikroklima und Boden in herzynischen Xerothermrasen haben sich u.a. HELMECKE (1972), REICHHOFF (1979, 1980) und SCHLÜTER & BALLER (1982) befaßt. Nicht unerwähnt bleiben sollen die grundlegenden Arbeiten von VOLK (1936, 1937b), HEILIG (1931) und DÖRR (1941)

Preprotein recognition and translocation by the Toc complex

Preproptein recognition and translocation across the outer envelope membrane of plastids is catalysed by a proteinaceous machinery, called Toc translocon. The Toc core complex is composed of the pore forming Toc75 and the two GTP-regulated receptors Toc159 and Toc34. A main issue of this work is the nature of preprotein recognition and transfer by this Toc apparatus. It is still under debate, whether Toc34 or Toc159 is the initial receptor. Here, using proteoliposomes with reconstituted either Toc core complex or Toc159 and Toc75 and several in vitro binding analysis Toc34 was shown to act upstream of Toc159. Moreover, a certain set of preproteins engages Toc64 before passing the Toc core complex. The receptor function and the dynamic association with the Toc core complex of this protein are established. Toc64 is the central component of the intermembrane space translocon. This complex migrates at approximately 700 kDa in a BN-PAGE and contains Toc64, Tic22, Toc12 and isHsp70. Toc12 is a novel identified Toc component, which exposes a J-domain toward the intermembrane space. This domain recruits isHsp70 to the intermembrane space translocon in an ATP and preprotein dependent manner. Finally, the work addresses the molecular identity of this isHsp70. Therefore, isHsp70 was purified by chromatographic approaches and analysed by mass spectroscopy. Several peptide masses were obtained, which reveal high similarity of P. sativum isHsp70 to S. oleracea Com70