74 citations · 684 across the 46 of their papers we have counts for
12 papers · 1 filter
Energy Extraction from Black Holes
Norbert Straumann
In this lecture I give an introduction to the rotational energy extraction of black holes by the electromagnetic Blandford-Znajek process and the generation of relativistic jets. A…
Josephson junctions and dark energy
Philippe Jetzer, Norbert Straumann
In a recent paper Beck and Mackey [astro-ph/0603397] argue that the argument we gave in our paper [Phys. Lett. B 606, 77 (2005)] to disprove their claim that dark energy can be dis…
Has Dark Energy really been discovered in the Lab?
Philippe Jetzer, Norbert Straumann
We show that Dark Energy contributions can not be determined from noise measurements of Josephson junctions, as was recently suggested in a paper by C. Beck and M.C. Mackey.
Cosmological Phase Transitions
Norbert Straumann
In this lecture at a school for condensed matter physicists, I begin with basic concepts and tools for investigating phase transitions in quantum field theory. The very different r…
On the Cosmological Constant Problems and the Astronomical Evidence for a Homogeneous Energy Density with Negative Pressure
Norbert Straumann
In this article the cosmological constant problems, as well as the astronomical evidence for a cosmologically significant homogeneous exotic energy density with negative pressure (…
Weak and Strong Lensing Statistics
Norbert Straumann
After a brief introduction to gravitational lensing theory, a rough overview of the types of gravitational lensing statistics that have been performed so far will be given. I shall…
On the mystery of the cosmic vacuum energy density
Norbert Straumann
After a short history of the -term it is explained why the (effective) cosmological constant is expected to obtain contributions from short-distance physics, corresponding to an…
The mystery of cosmological vacuum energy density and the accelerated expansion of the universe
Domenico Giulini, Norbert Straumann
The principles of General Relativity allow for a non-vanishing cosmological constant, which can possibly be interpreted at least partially in terms of quantum-fluctuations of matte…
Reflections on Gravity
Norbert Straumann
A pedagogical description of a simple ungeometrical approach to General Relativity is given, which follows the pattern of well understood field theories, such as electrodynamics. T…
The mystery of the cosmic vacuum energy density and the accelerated expansion of the Universe
N. Straumann
After a short history of the -term it is explained why the (effective) cosmological constant is expected to obtain contributions from short-distance-physics, corresponding to an…
The Membrane Model of Black Holes and Applications
Norbert Straumann
These lectures provide a detailed introduction to the electro- dynamics of black holes. A simplified derivation of the basic membrane equations for stationary, axisymmetric black h…
Complex Formulation of Lensing Theory and Applications
Norbert Straumann
The elegance and usefulness of a complex formulation of the basic lensing equations is demonstrated with a number of applications. Using standard tools of complex function theory,…