14,882 research outputs found
Flag manifolds and the Landweber-Novikov algebra
We investigate geometrical interpretations of various structure maps
associated with the Landweber-Novikov algebra S^* and its integral dual S_*. In
particular, we study the coproduct and antipode in S_*, together with the left
and right actions of S^* on S_* which underly the construction of the quantum
(or Drinfeld) double D(S^*). We set our realizations in the context of double
complex cobordism, utilizing certain manifolds of bounded flags which
generalize complex projective space and may be canonically expressed as toric
varieties. We discuss their cell structure by analogy with the classical
Schubert decomposition, and detail the implications for Poincare duality with
respect to double cobordism theory; these lead directly to our main results for
the Landweber-Novikov algebra.Comment: 23 pages. Published copy, also available at
http://www.maths.warwick.ac.uk/gt/GTVol2/paper5.abs.htm
Introduction: Special issue on genetic research of alcohol use disorder in diverse racial/ethnic populations
This special issue of The American Journal on Addictions is an extension of a workshop held at the Research Society on Alcoholism (2015) highlighting several important issues related to studies of the genetic bases of alcohol use disorder among racially/ethnically diverse populations. While not exhaustive in their coverage, the papers in this special issue focus on three important topics: (1) the importance of considering the social and environmental context in genetic analyses; (2) social and cultural considerations for engaging diverse communities in genetic research; and (3) methodologies related to phenotype development for use with racially/ethnically diverse populations. A brief overview of each paper included in these three sections is presented. The issue concludes with additional considerations for genetic research with racially/ethnically diverse population groups along with a commentary. (Am J Addict 2017;26:422–423
Theory of the high-frequency chiral optical response in a p_x+ip_y superconductor
The optical Hall conductivity and the polar Kerr angle are calculated as
functions of temperature for a two-dimensional chiral p_x+ip_y superconductor,
where the time-reversal symmetry is spontaneously broken. The theoretical
estimate for the polar Kerr angle agrees by the order of magnitude with the
recent experimental measurement in Sr2RuO4 by Xia et al. cond-mat/0607539. The
theory predicts that the Kerr angle is proportional to the square of the
superconducting energy gap and is inversely proportional to the cube of
frequency, which can be verified experimentally.Comment: 4 pages, no figures, RevTeX. V.2: one reference and discussion of
horizontal lines of nodes added. V.3: a typo corrected, and one reference
added. V.4: two references added and minor stylistic changes made, as in the
published versio
Spin-triplet pairing instability of the spinon Fermi surface in a U(1) spin liquid
Recent experiments on the organic compound \kappa-(ET)_2Cu_2(CN)_3 have
provided a promising example of a two dimensional spin liquid state. This phase
is described by a two-dimensional spinon Fermi sea coupled to a U(1) gauge
field. We study Kohn-Luttinger-like pairing instabilities of the spinon Fermi
surface due to singular interaction processes with twice-the-Fermi-momentum
transfer. We find that under certain circumstances the pairing instability
occurs in odd-orbital-angular-momentum/spin-triplet channels. Implications to
experiments are discussed.Comment: 4 pages, 1 figur
Irreducible modules over finite simple Lie conformal superalgebras of type K
We construct all finite irreducible modules over Lie conformal superalgebras
of type KComment: Accepted for publication in J. Math. Phys
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