5,342 research outputs found
Testing Electroweak Baryogenesis with Future Colliders
Electroweak Baryogenesis (EWBG) is a compelling scenario for explaining the
matter-antimatter asymmetry in the universe. Its connection to the electroweak
phase transition makes it inherently testable. However, completely excluding
this scenario can seem difficult in practice, due to the sheer number of
proposed models. We investigate the possibility of postulating a "no-lose"
theorem for testing EWBG in future e+e- or hadron colliders. As a first step we
focus on a factorized picture of EWBG which separates the sources of a stronger
phase transition from those that provide new sources of CP violation. We then
construct a "nightmare scenario" that generates a strong first-order phase
transition as required by EWBG, but is very difficult to test experimentally.
We show that a 100 TeV hadron collider is both necessary and possibly
sufficient for testing the parameter space of the nightmare scenario that is
consistent with EWBG.Comment: 26 pages + references, 10 figures. Fixed minor typos, updated TLEP
and 100 TeV projections. Conclusions unchange
T-Duality and Homological Mirror Symmetry of Toric Varieties
Let be a complete toric variety. The coherent-constructible
correspondence of \cite{FLTZ} equates \Perf_T(X_\Sigma) with a
subcategory Sh_{cc}(M_\bR;\LS) of constructible sheaves on a vector space
M_\bR. The microlocalization equivalence of \cite{NZ,N} relates these
sheaves to a subcategory Fuk(T^*M_\bR;\LS) of the Fukaya category of the
cotangent T^*M_\bR. When X_\Si is nonsingular, taking the derived category
yields an equivariant version of homological mirror symmetry,
DCoh_T(X_\Si)\cong DFuk(T^*M_\bR;\LS), which is an equivalence of
triangulated tensor categories.
The nonequivariant coherent-constructible correspondence of
\cite{T} embeds \Perf(X_\Si) into a subcategory
Sh_c(T_\bR^\vee;\bar{\Lambda}_\Si) of constructible sheaves on a compact
torus T_\bR^\vee. When X_\Si is nonsingular, the composition of
and microlocalization yields a version of homological mirror
symmetry, DCoh(X_\Sigma)\hookrightarrow DFuk(T^*T_\bR;\bar{\Lambda}_\Si),
which is a full embedding of triangulated tensor categories.
When X_\Si is nonsingular and projective, the composition is compatible with T-duality, in the following sense. An equivariant
ample line bundle \cL has a hermitian metric invariant under the real torus,
whose connection defines a family of flat line bundles over the real torus
orbits. This data produces a T-dual Lagrangian brane on the
universal cover T^*M_\bR of the dual real torus fibration. We prove \mathbb
L\cong \tau(\cL) in Fuk(T^*M_\bR;\LS). Thus, equivariant homological mirror
symmetry is determined by T-duality.Comment: 34 pages, 2 figures. The previous version of this paper has now been
broken into two parts. The other part is available at arXiv:1007.005
Evidence that natural selection maintains genetic variation for sleep in Drosophila melanogaster.
BackgroundDrosophila melanogaster often shows correlations between latitude and phenotypic or genetic variation on different continents, which suggests local adaptation with respect to a heterogeneous environment. Previous phenotypic analyses of latitudinal clines have investigated mainly physiological, morphological, or life-history traits. Here, we studied latitudinal variation in sleep in D. melanogaster populations from North and Central America. In parallel, we used RNA-seq to identify interpopulation gene expression differences.ResultsWe found that in D. melanogaster the average nighttime sleep bout duration exhibits a latitudinal cline such that sleep bouts of equatorial populations are roughly twice as long as those of temperate populations. Interestingly, this pattern of latitudinal variation is not observed for any daytime measure of activity or sleep. We also found evidence for geographic variation for sunrise anticipation. Our RNA-seq experiment carried out on heads from a low and high latitude population identified a large number of gene expression differences, most of which were time dependent. Differentially expressed genes were enriched in circadian regulated genes and enriched in genes potentially under spatially varying selection.ConclusionOur results are consistent with a mechanistic and selective decoupling of nighttime and daytime activity. Furthermore, the present study suggests that natural selection plays a major role in generating transcriptomic variation associated with circadian behaviors. Finally, we identified genomic variants plausibly causally associated with the observed behavioral and transcriptomic variation
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