Schrödinger

About: Schrödinger is a based out in . It is known for research contribution in the topics: Sputtering & Ion. The organization has 1621 authors who have published 2200 publications receiving 81554 citations.

Causality in inflationary universes with positive spatial curvature

Abstract: We show that in the case of positively-curved Friedmann-Lemaitre universes (k = +1), an inflationary period in the early universe will for most initial conditions not solve the horizon problem, no matter how long inflation lasts. It will only do so for cases where inflation starts in an almost static state, corresponding to an extremely high value of ΩΛ, ΩΛ ≫ 1, at the beginning of inflation. For smaller values, it is not possible to solve the horizon problem because the relevant integral asymptotes to a finite value (as happens also in the de Sitter universe in a k = +1 frame). Thus, for these cases, the causal problems associated with the near-isotropy of the Cosmic Background Radiation have to be solved already in the Planck era. Furthermore both compact space sections and event horizons will exist in these universes even if the present cosmological constant dies away in the far future, raising potential problems for M-theory as a theory of gravity.

Investigation of the spatial beam quality of pulsed ns-OPOs

Abstract: This paper reports on an experimental investigation of the spatial beam quality of a pulsed nanosecond optical parametric oscillator (OPO). The OPO is a 355 nm pumped type-I BBO-OPO. The spatial quality of the OPO output is characterized by the M2-parameter in dependence of other experimental parameters such as resonator length, pump-beam diameter, pump-pulse duration and pump energy. The results obtained indicate, that an appropriate choice of these parameters substantially improves the spatial beam quality of the OPO output.

Synthese von Bis(cyclopentadienyl)-1-metalla-3-phosphaindenen (M Titan, Zirkonium)

Abstract: Synthesis of Bis(cyclopentadienyl)-1-metalla-3-phosphaindenes (M= Titanium, Zirconium) The title compounds 7a, b were synthesised by heating the bis(cyclopentadienyl)diphenylmetal complexes 4a, b to 80°C in the presence of an excess of 2-tert-butyl-1-phosphaacetylene (6). The structure of 7a, b was determined by spectroscopic methods.