63,149 research outputs found
A rigorous solution concept for geodesic and geodesic deviation equations in impulsive gravitational waves
The geodesic as well as the geodesic deviation equation for impulsive
gravitational waves involve highly singular products of distributions
(\theta\de, \theta^2\de, \de^2). A solution concept for these equations
based on embedding the distributional metric into the Colombeau algebra of
generalized functions is presented. Using a universal regularization procedure
we prove existence and uniqueness results and calculate the distributional
limits of these solutions explicitly. The obtained limits are regularization
independent and display the physically expected behavior.Comment: RevTeX, 9 pages, final version (minor corrections, references added
The proton structure function F2 in the resonance region
Unique measurement of the proton structure function F2 in a wide
two-dimensional region of x and Q**2 has been reported. The accessible
kinematics covers entire resonance region up to W=2.5 GeV in the Q**2 interval
from 0.1 to 4.5 GeV**2. Obtained data allowed for the first time an evaluation
of moments of the structure function F2 directly from experimental data as well
as an intensive study of the Bloom-Gilman duality phenomenon.Comment: 6 pages, 4 figures, Proceedings of GDH2002 Conference, 3-6 July 2002,
Genova, Italy, to be published in World Scientifi
Recent results on the search for continuous sources with LIGO and GEO600
An overview of the searches for continuous gravitational wave signals in LIGO
and GEO 600 performed on different recent science runs and results are
presented. This includes both searching for gravitational waves from known
pulsars as well as blind searches over a wide parameter space.Comment: TAUP2005 Proceedings to be published in Journal of Physics:
Conference Serie
Convergence science in the Anthropocene: Navigating the known and unknown
Rapidly changing ecological and social systems currently pose significant societal challenges. Navigating the complexity of social-ecological change requires ap- proaches able to cope with, and potentially solve, both foreseen and unforeseen societal challenges.
The emergent field of convergence addresses the intricacies of such challenges, and is thus relevant to a broad range of interdisciplinary issues.
This paper suggests a way to conceptualize convergence research. It discusses how it relates to two major societal challenges (adaptation, transformation), and to the generation of policy-relevant science. It also points out limitations to the further development of convergence research
- …