13,611 research outputs found
Further search for a neutral boson with a mass around 9 MeV/c2
Two dedicated experiments on internal pair conversion (IPC) of isoscalar M1
transitions were carried out in order to test a 9 MeV/c2 X-boson scenario. In
the 7Li(p,e+e-)8Be reaction at 1.1 MeV proton energy to the predominantly T=0
level at 18.15 MeV, a significant deviation from IPC was observed at large pair
correlation angles. In the 11B(d,n e+e-)12C reaction at 1.6 MeV, leading to the
12.71 MeV 1+ level with pure T=0 character, an anomaly was observed at 9
MeV/c2. The compatibility of the results with the scenario is discussed.Comment: 12 pages, 5 figures, 2 table
Twisted Open Strings from Closed Strings: The WZW Orientation Orbifolds
Including {\it world-sheet orientation-reversing automorphisms}
in the orbifold program, we construct the operator
algebras and twisted KZ systems of the general WZW {\it orientation orbifold}
. We find that the orientation-orbifold sectors corresponding
to each are {\it twisted open} WZW strings, whose
properties are quite distinct from conventional open-string orientifold
sectors. As simple illustrations, we also discuss the classical (high-level)
limit of our construction and free-boson examples on abelian .Comment: 65 pages, typos correcte
A new tool to map the main worldviews in the Netherlands and USA, and explore how they relate to climate change
For addressing climate change, public support for changes in policy is needed, as well changes in individual lifestyles. Both of these appear to be intimately related with people's worldviews. Understanding these worldviews is therefore essential. In order to research and 'map' them, we translated the theoretical 'Integrative Worldview Framework' (IWF) into an empirical, quantitative approach. We constructed a worldview-scale aiming to distinguish between four major worldviews - labeled traditional, modern, postmodern, and integrative - and explored their interface with opinions and behaviors with respect to climate change. The survey was conducted with representative samples of citizens in the Netherlands and the USA (n = 527 and n = 556). The hypothesized worldviews were found in the data with a reasonable degree of reliability, especially in the Dutch sample. We also found consistent relationships between these worldview-clusters and a range of opinions, political priorities, and behaviors. In both countries postmoderns and integratives displayed significantly more concern about climate change as well as more sustainable behaviors, compared with moderns and traditionals. The implications of these findings for environmental policy and social science are noteworthy
Testing the membrane paradigm with holography
One version of the membrane paradigm states that as far as outside observers
are concerned, black holes can be replaced by a dissipative membrane with
simple physical properties located at the stretched horizon. We demonstrate
that such a membrane paradigm is incomplete in several aspects. We argue that
it generically fails to capture the massive quasinormal modes, unless we
replace the stretched horizon by the exact event horizon, and illustrate this
with a scalar field in a BTZ black hole background. We also consider as a
concrete example linearized metric perturbations of a five-dimensional
AdS-Schwarzschild black brane and show that a spurious excitation appears in
the long-wavelength response that is only removed from the spectrum when the
membrane paradigm is replaced by ingoing boundary conditions at the event
horizon. We interpret this excitation in terms of an additional Goldstone boson
that appears due to symmetry breaking by the classical solution ending on the
stretched horizon rather than the event horizon.Comment: 5 pages, 1 figure; v2: improved presentation, typos fixed, figure
fixed, conclusions unchanged; v3: further improvements in the presentation,
conclusions unchanged; v4: shortened, published versio
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