221 research outputs found
Novel 3d bosonic dualities from bosonization and holography
We use 3d bosonization dualities to derive new non-supersymmetric dualities
between bosonic quiver theories in dimensions. It is shown that such
dualities are a natural non-Abelian generalization of the bosonic
particle-vortex duality. A special case of such dualities is applicable to
Chern-Simons theories living on interfaces in dimensional
Yang-Mills theory across which the theta angle jumps. We also analyze such
interfaces in a holographic construction which provides further evidence for
novel dualities between quiver gauge theories and gauge theories with adjoint
scalars. These conjectured dualities pass some stringent consistency tests.Comment: 33+11 pages, 6 figures. v2: fixed minor typo
States are less likely to reform “three strikes” laws if they use them regularly and have higher levels of prison privatization
In the mid-1990s nearly half of U.S. states adopted “three strikes” laws, which impose lengthy sentences after a third serious conviction, as part of a “tough on crime” policy approach. Many states, however, began to reform or modify these laws in the 2000s. In new research, Matthew Cravens and Andrew Karch find that states that use their three strikes laws regularly were less likely to reform them if they had more extensive prison privatization and organized prison officer unions. In addition, those states with a higher proportion of African-American residents were also less likely to modify their laws. While fiscal pressures and political ideology also influenced reform, the results suggest that stakeholders seeking to maintain an incarceration-heavy status quo had an outsized influence
How looking only at policy diffusion "successes" between states may be misleading
Ideas often have a way of spreading. This is certainly true in the case of American states; innovative policies are often adopted by others in a process known as policy diffusion. But in trying to determine which policies spread, could we be giving too much of a focus on those that are successful? In new research which examines interstate compacts, Andrew Karch, Sean C. Nicholson-Crotty, Neal D. Woods, and Ann O’M. Bowman find that an emphasis on successful policies may be leading scholars to overestimate the importance of some factors, such as neighboring state activity, and underestimate the importance of others, like the number of previous adopters
Thermal Equilibration of Brane-Worlds
We analyze the thermodynamical properties of brane-worlds, with a focus on
the second model of Randall and Sundrum. We point out that during an
inflationary phase on the brane, black holes will tend to be thermally
nucleated in the bulk. This leads us to ask the question: Can the black hole -
brane-world system evolve towards a configuration of thermal equilibrium? To
answer this, we generalize the second Randall-Sundrum scenario to allow for
non-static bulk regions on each side of the brane-world. Explicitly, we take
the bulk to be a {\it Vaidya-AdS} metric, which describes the gravitational
collapse of a spherically symmetric null dust fluid in Anti-de Sitter
spacetime. Using the background subtraction technique to calculate the
Euclidean action, we argue that at late times a sufficiently large black hole
will relax to a point of thermal equilibrium with the brane-world environment.
These results have interesting implications for early-universe cosmology.Comment: 4 pages REVTeX. The basic argument is simplified. Version to appear
in Physics Letters
Localized modes at a D-brane--O-plane intersection and heterotic Alice strings
We study a system of -branes intersecting -branes and
-planes in 1+1-dimensions. We use anomaly cancellation and string dualities
to argue that there must be chiral fermion zero-modes on the -branes which
are localized near the -planes. Away from the orientifold limit we verify
this by using index theory as well as explicit construction of the zero-modes.
This system is related to F-theory on K3 and heterotic matrix string theory,
and the heterotic strings are related to Alice string defects in
Super-Yang-Mills. In the limit of large we find an
dual of the heterotic matrix string CFT.Comment: 44 pages, typos corrected, version published in JHE
The host metabolite D-serine contributes to bacterial niche specificity through gene selection
Escherichia coli comprise a diverse array of both commensals and niche-specific pathotypes. The ability to cause disease results from both carriage of specific virulence factors and regulatory control of these via environmental stimuli. Moreover, host metabolites further refine the response of bacteria to their environment and can dramatically affect the outcome of the host–pathogen interaction. Here, we demonstrate that the host metabolite, D-serine, selectively affects gene expression in E. coli O157:H7. Transcriptomic profiling showed exposure to D-serine results in activation of the SOS response and suppresses expression of the Type 3 Secretion System (T3SS) used to attach to host cells. We also show that concurrent carriage of both the D-serine tolerance locus (dsdCXA) and the locus of enterocyte effacement pathogenicity island encoding a T3SS is extremely rare, a genotype that we attribute to an ‘evolutionary incompatibility’ between the two loci. This study demonstrates the importance of co-operation between both core and pathogenic genetic elements in defining niche specificity
Equation of state of SiC at extreme conditions: new insight into the interior of carbon rich exoplanets
There is a direct relation between the composition of a host star and that of
the planets orbiting around it. As such, the recent discovery of stars with
unusual chemical composition, notably enriched in carbon instead of oxygen,
support the existence of exoplanets with a chemistry dominated by carbides
instead of oxides. Accordingly several studies have been recently conducted on
the Si C binary system at high pressure and temperature. Nonetheless, the
properties of carbides at the P T conditions of exoplanets interiors are still
inadequately constrained, effectively hampering reliable planetary modeling.
Here we present an in situ X ray diffraction study of the Si C binary system up
to 200 GPa and 3500 K, significantly enlarging the pressure range explored by
previous experimental studies. The large amount of collected data allows us to
properly investigate the phase diagram and to refine the Clapeyron slope of the
transition line from the zinc blende to the rock salt structure. Furthermore
the pressure volume temperature equation of state are provided for the high
pressure phase, characterized by low compressibility and thermal expansion. Our
results are used to model idealized C rich exoplanets of end members
composition. In particular, we derived mass radius relations and performed
numerical simulations defining rheological parameters and initial conditions
which lead to onset of convection in such SiC planets. We demonstrate that if
restrained to silicate rich mantle compositions, the interpretation of mass
radius relations may underestimate the interior diversity of exoplanets.Comment: 30 Pages, 8 Figure
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