3,224 research outputs found
Towards a classification of branes in theories with eight supercharges
We provide a classification of half-supersymmetric branes in quarter-maximal
supergravity theories with scalars parametrising coset manifolds. Guided by the
results previously obtained for the half-maximal theories, we are able to show
that half-supersymmetric branes correspond to the real longest weights of the
representations of the brane charges, where the reality properties of the
weights are determined from the Tits-Satake diagrams associated to the global
symmetry groups. We show that the resulting brane structure is universal for
all theories that can be uplifted to six dimensions. We also show that when
viewing these theories as low-energy theories for the suitably compactified
heterotic string, the classification we obtain is in perfect agreement with the
wrapping rules derived in previous works for the same theory compactified on
tori. Finally, we relate the branes to the R-symmetry representations of the
central charges and we show that in general the degeneracies of the BPS
conditions are twice those of the half-maximal theories and four times those of
the maximal ones.Comment: 47 pages, 8 figure
Ribosome traffic on mRNAs maps to gene ontology : genome-wide quantification of translation initiation rates and polysome size regulation
Peer reviewedPublisher PD
Experimental investigation on free surface vortices driven by tangential inlets
Particle Image Velocimetry (PIV) measurements have been carried out in order to analyze the structure of free surface vortices in a promoting geometry with two tangential inlets. Velocity fields associated to the free surface vortex have been obtained at different horizontal planes and Reynolds numbers. Average velocity fields have been calculated and tangential velocity profiles have been compared at different vortex stages and measurement planes. The results show that tangential flow is uniform along the vortex axis and it scales well with the average exit velocity. The tangential velocity profiles, in comparison to the potential behavior, show discrepancies especially at large distances from the vortex axis. Vorticity fields and circulation profiles have been also derived from the measured velocity fields and discussed. The circulation profiles increase along the vortex radius even at large distances from the vortex axis, so that the potential solution is not applicable at all. The comparison of tangential velocity and circulation profiles between promoted and free vortices, the last presented in a previous paper, shows that the tangential motion in a driven vortex is more intense and predominant over the sink effect (radial motion), except very close to the tank bottom, as in a forced configuration (i.e. rotating cylindrical tank)
Sistemi VoIP con apparati di diversi produttori: soluzioni di problemi di interoperabilità e progetto di servizi avanzati
interoperabilità fra il centralino VoIP Dexgatemicro e quello Asterisk; progetto servizi di Hold e Transfer di una chiamata in Dexgatemicro utilizzando i tasti hold e transfer presenti sui telefon
Non-Relativistic Heterotic String Theory
In this work we consider heterotic-gravity as the low-energy approximation to
heterotic string theory. We define a consistent non-relativistic limit of
heterotic gravity that includes the Yang-Mills Chern-Simons term. We perform
three tests on the heterotic limit: we use it to (i) derive the
non-relativistic transformation rules, (ii) show the existence of a finite
non-relativistic heterotic action and (iii) obtain the longitudinal
non-relativistic T-duality rules. We show that in all these cases the limit
procedure is well defined, free of divergences and leads to consistent
non-trivial results. We comment on the interpretation of the T-duality rules in
terms of a heterotic non-relativistic geometry underlying non-relativistic
heterotic string theory.Comment: 12 page
- …