16,541 research outputs found
Developing educational iPhone, Android and Windows smartphone cross-platform apps to facilitate understanding of clinical genomics terminology
No abstract available
Conformal correlators of mixed-symmetry tensors
We generalize the embedding formalism for conformal field theories to the
case of general operators with mixed symmetry. The index-free notation encoding
symmetric tensors as polynomials in an auxiliary polarization vector is
extended to mixed-symmetry tensors by introducing a new commuting or
anticommuting polarization vector for each row or column in the Young diagram
that describes the index symmetries of the tensor. We determine the tensor
structures that are allowed in n-point conformal correlation functions and give
an algorithm for counting them in terms of tensor product coefficients. A
simple derivation of the unitarity bound for arbitrary mixed-symmetry tensors
is obtained by considering the conservation condition in embedding space. We
show, with an example, how the new formalism can be used to compute conformal
blocks of arbitrary external fields for the exchange of any conformal primary
and its descendants. The matching between the number of tensor structures in
conformal field theory correlators of operators in d dimensions and massive
scattering amplitudes in d+1 dimensions is also seen to carry over to
mixed-symmetry tensors.Comment: 46 pages, many figures, v2: Reformulated the counting of tensor
structures, new section on conserved operators, v3: fixed typo
Coaxial cable stripping device facilitates RF cabling fabrication
Coaxial cable stripping device assures clean, right angled shoulder for RF cable connector fabrication. This method requires minimal skill and creates a low voltage standing wave ratio and mechanical stability in the interconnecting RF Cables
Magnetic excitations in a bond-centered stripe phase: Spin waves far from the semi-classical limit
Using a spin-only model, we compute spin excitation spectra in a
bond-centered stripe state with long-range magnetic order. We employ a bond
operator formalism, which naturally captures both dimerization and broken spin
symmetry in a unified framework. At low energies, the spin excitations resemble
spin waves, but at higher energies they are very similar to spin-1 excitations
of isolated spin ladders. Our theory does well describe neutron scattering data
[J. M. Tranquada et al., Nature 429, 534 (2004)] on LaBaCuO, pointing towards
bond order in this material.Comment: 4 pages, 3 figs, of possible relevance to experiments reported in
cond-mat/0401621; (v2) final version as publishe
Beyond Rainbow-Ladder in bound state equations
In this work we devise a new method to study quark anti-quark interactions
beyond simple ladder-exchange that yield massless pions in the chiral limit.
The method is based on the requirement to have a representation of the
quark-gluon vertex that is explicitly given in terms of quark dressings
functions. We outline a general procedure to generate the Bethe-Salpeter kernel
for a given vertex representation. Our method allows not only the
identification of the mesons' masses but also the extraction of their
Bethe-Salpeter wave functions exposing their internal structure. We exemplify
our method with vertex models that are of phenomenological interest.Comment: 13 pages, 6 figures; v2: typos corrected, colors improve
Other-regarding behaviour: Testing guilt- and reciprocity-based models
We analyse two types of belief-dependant models of social preferences: guilt aversion and reciprocity. In particular, we test the relevance of their input variables (second-order beliefs and general dispositions for guilt/reciprocity). The data confirm the predictions of belief-dependant models. Both second-order beliefs and a participant's sensitivity to guilt/reciprocity are relevant for the decisions taken. Second-order beliefs appear to have an inverse U-shaped effect on the extent of kind behaviour.social preferences, other-regarding behaviour, belief-dependent models, experiments, trust game, guilt aversion, beliefs, psychological game theory, emotions, reciprocity
- …