6,620 research outputs found
Tiling Spaces are Inverse Limits
Let M be an arbitrary Riemannian homogeneous space, and let Omega be a space
of tilings of M, with finite local complexity (relative to some symmetry group
Gamma) and closed in the natural topology. Then Omega is the inverse limit of a
sequence of compact finite-dimensional branched manifolds. The branched
manifolds are (finite) unions of cells, constructed from the tiles themselves
and the group Gamma. This result extends previous results of Anderson and
Putnam, of Ormes, Radin and Sadun, of Bellissard, Benedetti and Gambaudo, and
of G\"ahler. In particular, the construction in this paper is a natural
generalization of G\"ahler's.Comment: Latex, 6 pages, including one embedded figur
Fractal space-times under the microscope: A Renormalization Group view on Monte Carlo data
The emergence of fractal features in the microscopic structure of space-time
is a common theme in many approaches to quantum gravity. In this work we carry
out a detailed renormalization group study of the spectral dimension and
walk dimension associated with the effective space-times of
asymptotically safe Quantum Einstein Gravity (QEG). We discover three scaling
regimes where these generalized dimensions are approximately constant for an
extended range of length scales: a classical regime where , a
semi-classical regime where , and the UV-fixed point
regime where . On the length scales covered by
three-dimensional Monte Carlo simulations, the resulting spectral dimension is
shown to be in very good agreement with the data. This comparison also provides
a natural explanation for the apparent puzzle between the short distance
behavior of the spectral dimension reported from Causal Dynamical
Triangulations (CDT), Euclidean Dynamical Triangulations (EDT), and Asymptotic
Safety.Comment: 26 pages, 6 figure
Caracterización reológica del suero de tofu a temperaturas próximas a la congelación
El suero de tofu es un subproducto obtenido en la producciónindustrial a partir de la leche de soja. Este suero tiene componentes beneficiosos para la salud, como su contenidoen isoflavonas. Caracterizar reológicamente el suero de tofu a bajas temperaturas tiene interés con el fin de facilitar la recuperación de este efluente y sus compuestos activos sin que se deterioren. Además puede suponer una importante reducción del impacto ambiental debido a la elevada carga orgánica.En el presente trabajo se ha determinado un comportamientoreológico newtoniano en las muestras de suero fresco a 1,9 ºBrix inicial, crioconcentrado hasta 18,5º Brix y posteriormente evaporado hasta 60,2ºBrix. El rango de temperaturas ensayadas es próximo a la congelación (de -4ºC a 4ºC) debido al interés de ser procesadas bajo las condiciones que puedan preservar los compuestos activos
Molecular basis of sweet taste in dipeptide taste ligands
Abstract
In this presentation, we describe an integrated approach for the molecular basis for sweet taste among dipeptide-based ligands. By comparing the results obtained from X-ray diffraction studies with the conformations from NMR analysis and molecular modeling, we have observed recurring topochemical motifs that agree with previous models for sweet taste. In our examination of the unexplored D zone of the TintiNofre model, we have uncovered a sweet potency enhancing effect of a new set of aralkyl-substitutions on dipeptide ligands, which reveals the importance of aromaticaromatic interactions in maintaining high potency
Cosmological measurements, time and observables in (2+1)-dimensional gravity
We investigate the relation between measurements and the physical observables
for vacuum spacetimes with compact spatial surfaces in (2+1)-gravity with
vanishing cosmological constant. By considering an observer who emits lightrays
that return to him at a later time, we obtain explicit expressions for several
measurable quantities as functions on the physical phase space of the theory:
the eigentime elapsed between the emission of a lightray and its return to the
observer, the angles between the directions into which the light has to be
emitted to return to the observer and the relative frequencies of the lightrays
at their emission and return. This provides a framework in which conceptual
questions about time, observables and measurements can be addressed. We analyse
the properties of these measurements and their geometrical interpretation and
show how they allow an observer to determine the values of the Wilson loop
observables that parametrise the physical phase space of (2+1)-gravity. We
discuss the role of time in the theory and demonstrate that the specification
of an observer with respect to the spacetime's geometry amounts to a gauge
fixing procedure yielding Dirac observables.Comment: 38 pages, 11 eps figures, typos corrected, references update
Grafting and Poisson structure in (2+1)-gravity with vanishing cosmological constant
We relate the geometrical construction of (2+1)-spacetimes via grafting to
phase space and Poisson structure in the Chern-Simons formulation of
(2+1)-dimensional gravity with vanishing cosmological constant on manifolds of
topology , where is an orientable two-surface of genus
. We show how grafting along simple closed geodesics \lambda is
implemented in the Chern-Simons formalism and derive explicit expressions for
its action on the holonomies of general closed curves on S_g. We prove that
this action is generated via the Poisson bracket by a gauge invariant
observable associated to the holonomy of . We deduce a symmetry
relation between the Poisson brackets of observables associated to the Lorentz
and translational components of the holonomies of general closed curves on S_g
and discuss its physical interpretation. Finally, we relate the action of
grafting on the phase space to the action of Dehn twists and show that grafting
can be viewed as a Dehn twist with a formal parameter satisfying
.Comment: 43 pages, 10 .eps figures; minor modifications: 2 figures added,
explanations added, typos correcte
The effect of display rules on illusion of transparency in children
The illusion of transparency, the tendency for people to overestimate how obvious their internal states appear to outside observers, was examined in 25 school-age children. While previous researchers studied undergraduate participants, we aimed to expand the developmental literature by investigating whether children exhibit the illusion of transparency in the same manner as undergraduates. We presented each child with three pleasant-tasting drinks and two unpleasant-tasting drinks. Two undergraduate observers and the children rated facial expressions after each sip. Our results supported our hypothesis with no illusion of transparency for the unpleasant drinks; however, an illusion was found for the pleasant drinks. The children\u27s inability to follow display rules may explain the absence of the illusion of transparency for the unpleasant condition
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