The Reeh-Schlieder property for thermal field theories

We show that the Reeh-Schlieder property w.r.t. the KMS-vector is a direct consequence of locality, additivity and the relativistic KMS-condition. The latter characterises the thermal equilibrium states of a relativistic quantum field theory. The statement remains vaild even if the given equilibrium state breaks spatial translation invariance.Comment: plain tex, 10 page

A Goldstone Theorem in Thermal Relativistic Quantum Field Theory

We prove a Goldstone Theorem in thermal relativistic quantum field theory, which relates spontaneous symmetry breaking to the rate of space-like decay of the two-point function. The critical rate of fall-off coincides with that of the massless free scalar field theory. Related results and open problems are briefly discussed

Thermal Quantum Fields without Cut-offs in 1+1 Space-time Dimensions

We construct interacting quantum fields in 1+1 dimensional Minkowski space, representing neutral scalar bosons at positive temperature. Our work is based on prior work by Klein and Landau and Hoegh-KrohnComment: 48 page

On the mixing property for a class of states of relativistic quantum fields

Let $\omega$ be a factor state on the quasi-local algebra $\cal{A}$ of observables generated by a relativistic quantum field, which in addition satisfies certain regularity conditions (satisfied by ground states and the recently constructed thermal states of the $P(\phi)_2$ theory). We prove that there exist space and time translation invariant states, some of which are arbitrarily close to $\omega$ in the weak* topology, for which the time evolution is weakly asymptotically abelian

Microlocal analysis of quantum fields on curved spacetimes: Analytic wavefront sets and Reeh-Schlieder theorems

We show in this article that the Reeh-Schlieder property holds for states of quantum fields on real analytic spacetimes if they satisfy an analytic microlocal spectrum condition. This result holds in the setting of general quantum field theory, i.e. without assuming the quantum field to obey a specific equation of motion. Moreover, quasifree states of the Klein-Gordon field are further investigated in this work and the (analytic) microlocal spectrum condition is shown to be equivalent to simpler conditions. We also prove that any quasifree ground- or KMS-state of the Klein-Gordon field on a stationary real analytic spacetime fulfills the analytic microlocal spectrum condition.Comment: 31 pages, latex2

Forest albedo in the context of different cloud situations derived from irradiance measurements at the Leipzig floodplain crane: A pilot study

The surface albedo significantly modulates the atmospheric energy budget and, thus, vertical radiation, energy, and mass fluxes. Therefore, it regulates the local and regional effects of climate warming. Over a forest canopy, the surface albedo mainly depends on the seasonal leaf state. Furthermore, for certain surface types, such as snow, it has been shown that the surface albedo changes as a function of cloudiness. A similar effect is expected over forest surfaces, leading to complex feedback loops between forest surfaces and climate. To investigate these processes, a pilot study was performed at the Leipzig floodplain crane to observe the forest canopy albedo under different atmospheric conditions in 2021. First analyses revealed a dependency of the forest albedo from the cloud state, which is slightly stronger in the near-infrared wavelength range compared to the visible wavelength range.Der atmosphärische Strahlungshaushalt und damit auch die vertikale Strahlungsverteilung, Energie- und Massenflüsse werden signifikant durch die Bodenalbedo gesteuert. Diese regulieren somit lokale und regionale Effekte der Klimaerwärmung. Über einem Wald hängt die Bodenalbedo hauptsächlich vom saisonalen Blattstatus ab. Zudem wurde für bestimmte Bodentypen wie Schneeoberflächen gezeigt, dass die Bodenalbedo eine Funktion der Bewölkung ist. Ähnlicher Effekte werden für Waldoberflächen erwartet, welche zu komplexen Rückkopplungseffekten zwischenWaldoberflächen und dem Klima führen. Um diese Prozesse zu untersuchen wurde im Jahr 2021 eine Vorstudie am Leipziger Auwaldkran durchgeführt, um die Waldalbedo unter verschiedenen atmosphärischen Bedingungen zu beobachten. Erste Analysen zeigen, dass auch die Albedo des Waldes von den Bewölkungsbedingungen abhängt. Der Effekt ist dabei etwas stärker im nah-infrarotem als im sichtbaren Wellenlängenbereich zu beobachten

Cycloadditionen am Azulensystem

Cycloadditionen am Azulensystem waren bisher nicht bekannt. Vielmehr reagiert Azulen z. B. mit Maleinsäureanhydrid unter „addierender Substitution" zum 1-Azulenyl- bernsteinsäureanhydrid und mit Tetracyanäthylen zum 1-Tricyanvinyl-azulen[¹]

Intense high-quality medical proton beams via laser fields

During the past decade, the interaction of high-intensity lasers with solid targets has attracted much interest, regarding its potential in accelerating charged particles. In spite of tremendous progress in laser-plasma based acceleration, it is still not clear which particle beam quality will be accessible within the upcoming multi petawatt (1 PW = 10$^{15}$ W) laser generation. Here, we show with simulations based on the coupled relativistic equations of motion that protons stemming from laser-plasma processes can be efficiently post-accelerated using crossed laser beams focused to spot radii of a few laser wavelengths. We demonstrate that the crossed beams produce monoenergetic accelerated protons with kinetic energies $> 200$ MeV, small energy spreads ($\approx$ 1$$) and high densities as required for hadron cancer therapy. To our knowledge, this is the first scheme allowing for this important application based on an all-optical set-up.Comment: 14 pages, 3 figures, 1 tabl

Cycloadditions to the Azulene System

Cycloadditions to the azulene system have not hitherto been observed. Instead, azulene reacts, e.g., with maleic anhydride via an "addition-substitution route" to give 1-azulenylsuccinic anhydride and with tetracyanoethylene to yield 1-tricy-anovinylazulene[¹]