Multiphoton Bloch-Siegert shifts and level-splittings in spin-one systems

We consider a spin-boson model in which a spin 1 system is coupled to an oscillator. A unitary transformation is applied which allows a separation of terms responsible for the Bloch-Siegert shift, and terms responsible for the level splittings at anticrossings associated with Bloch-Siegert resonances. When the oscillator is highly excited, the system can maintain resonance for sequential multiphoton transitions. At lower levels of excitation, resonance cannot be maintained because energy exchange with the oscillator changes the level shift. An estimate for the critical excitation level of the oscillator is developed.Comment: 14 pages, 3 figure

Teoria idei Platona a matematyka

Przekład z języka niemieckiego artykułu Hermanna Cohen'a

Ästhetik des reinen Gefühls

von Hermann CohenErschienen: Bd. 1 -

Von Kants Einfluss auf die deutsche Kultur

Tłumaczenia dokonano na podstawie H. Cohen: Von Kants Einfluss auf die deutsche Kultur. Rede bei der Marburger Universitäts-Feier des Geburtstages Sr. Majestät des Kaisers und Königs am 17. März 1883 gehalten. Berlin 1883.[...] Pozwolę sobie dzisiaj Państwu powiedzieć o wpływie Kanta na kulturę niemiecką - w jubileuszowym roku wydania pisma Kanta, które w swym tytule wypowiada już zarówno istotną myśl przewodnią, jak i reformatorską świadomość autora: „Prolegomena do wszelkiej przyszłej metafizyki, która będzie mogła wystąpić jako nauka”. Rzeczywiście, tytuł ten pozwala się przekonać o historycznym wpływie Kanta. Celem Kanta nie było zakończenie wszelkich filozoficznych przedsięwzięć, ani też wyczarowanie w języku swej książki ducha przyszłego myślenia. Chciał on napisać Prolegomena do wszelkiej przyszłej metafizyki, metodyczne wprowadzenie. Na roszczeniu ograniczenia metafizyki, „która będzie mogła wystąpić jako nauka”, polega jego dziejowa misja. W zwrocie „jako nauka” zawiera się to, co wyróżnia system Kanta: metoda Kantowska. Odtąd nie boskie szaleństwo winno uskrzydlać geniusza mądrości, nie dumna rezygnacja scio me veram intelligere philosophiam z poczucia prawdy ostatecznych podstaw mądrości, lecz metafizyka powinna stać się nauką, ma zostać wprowadzona na „stałą drogę nauki”. Taki wyjątkowo historyczny sens ma myślenie Kantowskie. Tymczasem z tego wynika właśnie, w jakim kierunku i sposobie - i nie jest to metafora - jak szybko rozchodzi się historyczny wpływ Kanta [...

Algebraic nonlinear collective motion

Finite-dimensional Lie algebras of vector fields determine geometrical collective models in quantum and classical physics. Every set of vector fields on Euclidean space that generates the Lie algebra sl(3, R) and contains the angular momentum algebra so(3) is determined. The subset of divergence-free sl(3, R) vector fields is proven to be indexed by a real number $\Lambda$. The $\Lambda=0$ solution is the linear representation that corresponds to the Riemann ellipsoidal model. The nonlinear group action on Euclidean space transforms a certain family of deformed droplets among themselves. For positive $\Lambda$, the droplets have a neck that becomes more pronounced as $\Lambda$ increases; for negative $\Lambda$, the droplets contain a spherical bubble of radius $|\Lambda|^{{1/3}}$. The nonlinear vector field algebra is extended to the nonlinear general collective motion algebra gcm(3) which includes the inertia tensor. The quantum algebraic models of nonlinear nuclear collective motion are given by irreducible unitary representations of the nonlinear gcm(3) Lie algebra. These representations model fissioning isotopes ($\Lambda>0$) and bubble and two-fluid nuclei ($\Lambda<0$).Comment: 32pages, 4 figures not include

Choosing a basis that eliminates spurious solutions in k.p theory

A small change of basis in k.p theory yields a Kane-like Hamiltonian for the conduction and valence bands of narrow-gap semiconductors that has no spurious solutions, yet provides an accurate fit to all effective masses. The theory is shown to work in superlattices by direct comparison with first-principles density-functional calculations of the valence subband structure. A reinterpretation of the standard data-fitting procedures used in k.p theory is also proposed.Comment: 15 pages, 2 figures; v3: expanded with much new materia

Nitrous oxide cycling in the Arabian Sea

Depth profiles of dissolved nitrous oxide (N2O) were measured in the central and western Arabian Sea during four cruises in May and July–August 1995 and May–July 1997 as part of the German contribution to the Arabian Sea Process Study of the Joint Global Ocean Flux Study. The vertical distribution of N2O in the water column on a transect along 65°E showed a characteristic double-peak structure, indicating production of N2O associated with steep oxygen gradients at the top and bottom of the oxygen minimum zone. We propose a general scheme consisting of four ocean compartments to explain the N2O cycling as a result of nitrification and denitrification processes in the water column of the Arabian Sea. We observed a seasonal N2O accumulation at 600–800 m near the shelf break in the western Arabian Sea. We propose that, in the western Arabian Sea, N2O might also be formed during bacterial oxidation of organic matter by the reduction of IO3 − to I−, indicating that the biogeochemical cycling of N2O in the Arabian Sea during the SW monsoon might be more complex than previously thought. A compilation of sources and sinks of N2O in the Arabian Sea suggested that the N2O budget is reasonably balanced

Tailored carrier/bacteria technology for rehabilitation of areas with pesticide-containing pollution – AQUAREHAB WP2

Postprint (published version

Challenges in network science: Applications to infrastructures, climate, social systems and economics

Network theory has become one of the most visible theoretical frameworks that can be applied to the description, analysis, understanding, design and repair of multi-level complex systems. Complex networks occur everywhere, in man-made and human social systems, in organic and inorganic matter, from nano to macro scales, and in natural and anthropogenic structures. New applications are developed at an ever-increasing rate and the promise for future growth is high, since increasingly we interact with one another within these vital and complex environments. Despite all the great successes of this field, crucial aspects of multi-level complex systems have been largely ignored. Important challenges of network science are to take into account many of these missing realistic features such as strong coupling between networks (networks are not isolated), the dynamics of networks (networks are not static), interrelationships between structure, dynamics and function of networks, interdependencies in given networks (and other classes of links, including different signs of interactions), and spatial properties (including geographical aspects) of networks. This aim of this paper is to introduce and discuss the challenges that future network science needs to address, and how different disciplines will be accordingly affected. Graphical abstrac