68,872 research outputs found
Z-graded weak modules and regularity
It is proved that if any Z-graded weak module for vertex operator algebra V
is completely reducible, then V is rational and C_2-cofinite. That is, V is
regular. This gives a natural characterization of regular vertex operator
algebras.Comment: 9 page
Quasiperiodic, periodic, and slowing-down states of coupled heteroclinic cycles
We investigate two coupled oscillators, each of which shows an attracting heteroclinic cycle in the absence of coupling. The two heteroclinic cycles are nonidentical. Weak coupling can lead to the elimination of the slowing-down state that asymptotically approaches the heteroclinic cycle for a single cycle, giving rise to either quasiperiodic motion with separate frequencies from the two cycles or periodic motion in which the two cycles are synchronized. The synchronization transition, which occurs via a Hopf bifurcation, is not induced by the commensurability of the two cycle frequencies but rather by the disappearance of the weaker frequency oscillation. For even larger coupling the motion changes via a resonant heteroclinic bifurcation to a slowing-down state corresponding to a single attracting heteroclinic orbit. Coexistence of multiple attractors can be found for some parameter regions. These results are of interest in ecological, sociological, neuronal, and other dynamical systems, which have the structure of coupled heteroclinic cycles
Hydrogen-bonded liquid crystals with broad-range blue phases
We report a modular supramolecular approach for the investigation of chirality induction in hydrogen-bonded liquid crystals. An exceptionally broad blue phase with a temperature range of 25 °C was found, which enabled its structural investigation by solid state 19F-NMR studies and allowed us to report order parameters of the blue phase I for the first time
Logarithmic intertwining operators and vertex operators
This is the first in a series of papers where we study logarithmic
intertwining operators for various vertex subalgebras of Heisenberg vertex
operator algebras. In this paper we examine logarithmic intertwining operators
associated with rank one Heisenberg vertex operator algebra , of
central charge . We classify these operators in terms of {\em depth}
and provide explicit constructions in all cases. Furthermore, for we
focus on the vertex operator subalgebra L(1,0) of and obtain
logarithmic intertwining operators among indecomposable Virasoro algebra
modules. In particular, we construct explicitly a family of {\em hidden}
logarithmic intertwining operators, i.e., those that operate among two ordinary
and one genuine logarithmic L(1,0)-module.Comment: 32 pages. To appear in CM
Exploring the link between more negative osmotic potential and ryegrass summer performance
This paper outlines recent research studying within-population variation in selected New Zealand perennial ryegrass cultivars, for traits related to tolerance of summer moisture deficit. Two clonal replicates of 220 genotypes from ‘Grasslands Nui’ (Nui, n=50), ‘Grasslands Samson’ Samson, n=80), and ‘Trojan’ (n=90) were exposed to a 1 month of moisture deficit challenge, with plant water relations measurements performed to evaluate putative drought-response mechanisms. Water use of individual genotypes ranged from 1000 g water/g DM indicating large within-population variation for this trait. Mean WUE for Nui, Samson, and Trojan was, respectively, 424±16, 412±10, and 319±9 g water/g DW (P<0.001), suggesting that commercial plant breeding may have indirectly reduced water use in modern cultivars without specific focus on water relations. Principal component analysis indicated more negative osmotic potential may contribute to reduced water use while maintaining yield under water deficit, giving a potential focus for future breeding selection targeting summer water deficit tolerance.fals
Estimating coherence measures from limited experimental data available
Quantifying coherence has received increasing attention, and considerable
work has been directed towards finding coherence measures. While various
coherence measures have been proposed in theory, an important issue following
is how to estimate these coherence measures in experiments. This is a
challenging task, since the state of a system is often unknown in practical
applications and the accessible measurements in a real experiment are typically
limited. In this Letter, we put forward an approach to estimate coherence
measures of an unknown state from any limited experimental data available. Our
approach is not only applicable to coherence measures but can be extended to
other resource measures.Comment: 7 pages, 2 figure
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