5,713 research outputs found
Satisfying states of triangulations of a convex n-gon
In this work we count the number of satisfying states of triangulations of a
convex n-gon using the transfer matrix method. We show an exponential (in n)
lower bound. We also give the exact formula for the number of satisfying states
of a strip of triangles.Comment: 17 pages, 6 figure
Directed cycle double covers: structure and generation of hexagon graphs
Jaeger's directed cycle double cover conjecture can be formulated as a
problem of existence of special perfect matchings in a class of graphs that we
call hexagon graphs. In this work, we explore the structure of hexagon graphs.
We show that hexagon graphs are braces that can be generated from the ladder on
8 vertices using two types of McCuaig's augmentations.Comment: 20 page
Black hole elasticity and gapped transverse phonons in holography
We study the elastic response of planar black hole (BH) solutions in a simple
class of holographic models with broken translational invariance. We compute
the transverse quasi-normal mode spectrum and the propagation speed of the
lowest energy mode. We find that the speed of the lowest mode relates to the BH
rigidity modulus as dictated by elasticity theory. This allows to identify
these modes as transverse phonons---the pseudo Goldstone bosons of
spontaneously broken translational invariance. In addition, we show that these
modes have a mass gap controlled by an explicit source of the translational
symmetry breaking. These results provide a new confirmation that the BHs in
these models do exhibit solid properties that become more manifest at low
temperatures. Also, by the AdS/CFT correspondence, this allows to extend the
standard results from the effective field theory for solids to quantum-critical
materials.Comment: 28 pages, 7 figures; v3: minor revisions, matching JHEP published
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Current status of las tablas de daimiel national park wetland and actions required for conservation
Wetlands are complex ecosystems that play multiple roles. âLas Tablas de Daimiel National Parkâ (TDNP) undoubtedly plays a role in several ecosystem services and provides a connection between nature, farmers, scientists, residents, and other stakeholders. The state of degradation and/or vulnerability of this ecosystem (with a series of socio-economic implications) have led the publication of numerous articles. The work reported here provides a description of the growing importance of this wetland within the rural landscapes of La Mancha and emphasizes its state of degradation, mainly since pedological point of view. In this way, particular attention is required to assure the conservation of the Tablas of Daimiel Wetland; thus, several measures are proposed to improve the conservation of this area as to control and prohibit any dumping of any type of waste in the park or in its vicinityThis Research was funded by Organismo Autonomo Parques Nacionales (Autonomous Organism National Parks) of Spain (OAPN
Rate-induced tipping and saddle-node bifurcation for quadratic differential equations with nonautonomous asymptotic dynamics
An in-depth analysis of nonautonomous bifurcations of saddle-node
type for scalar differential equations ,
where and are bounded and uniformly
continuous, is fundamental to explain the absence or occurrence of
rate-induced tipping for the differential equation
as the rate varies on .
A classical attractor-repeller pair, whose existence for is assumed,
may persist for any , or disappear for a certain critical rate ,
giving rise to rate-induced tipping. A suitable example demonstrates that
this tipping phenomenon may be reversible.Marie SkĆodowska-Curie grant agreement No 643073Ministerio de Ciencia, InnovaciĂłn y Universidades, RTI2018-096523-B-I00Marie SkĆodowska-Curie grant agreement No 75446
G-inverses for random walks
Postprint (published version
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