3,041 research outputs found
H\"older Regularity of Geometric Subdivision Schemes
We present a framework for analyzing non-linear -valued
subdivision schemes which are geometric in the sense that they commute with
similarities in . It admits to establish
-regularity for arbitrary schemes of this type, and
-regularity for an important subset thereof, which includes all
real-valued schemes. Our results are constructive in the sense that they can be
verified explicitly for any scheme and any given set of initial data by a
universal procedure. This procedure can be executed automatically and
rigorously by a computer when using interval arithmetics.Comment: 31 pages, 1 figur
Quark-Hadron Phase Transitions in Viscous Early Universe
Based on hot big bang theory, the cosmological matter is conjectured to
undergo QCD phase transition(s) to hadrons, when the universe was about s old. In the present work, we study the quark-hadron phase transition, by
taking into account the effect of the bulk viscosity. We analyze the evolution
of the quantities relevant for the physical description of the early universe,
namely, the energy density , temperature , Hubble parameter and
scale factor before, during and after the phase transition. To study the
cosmological dynamics and the time evolution we use both analytical and
numerical methods. By assuming that the phase transition may be described by an
effective nucleation theory (prompt {\it first-order} phase transition), we
also consider the case where the universe evolved through a mixed phase with a
small initial supercooling and monotonically growing hadronic bubbles. The
numerical estimation of the cosmological parameters, and for instance,
makes it clear that the time evolution varies from phase to phase. As the QCD
era turns to be fairly accessible in the high-energy experiments and the
lattice QCD simulations, the QCD equation of state is very well defined. In
light of this, we introduce a systematic study of the {\it cross-over}
quark-hadron phase transition and an estimation for the time evolution of
Hubble parameter.Comment: 27 pages, 17 figures, revtex style (To appear in Phys. Rev. D). arXiv
admin note: text overlap with arXiv:gr-qc/040404
Cross-Dimensional relaxation in Bose-Fermi mixtures
We consider the equilibration rate for fermions in Bose-Fermi mixtures
undergoing cross-dimensional rethermalization. Classical Monte Carlo
simulations of the relaxation process are performed over a wide range of
parameters, focusing on the effects of the mass difference between species and
the degree of initial departure from equilibrium. A simple analysis based on
Enskog's equation is developed and shown to be accurate over a variety of
different parameter regimes. This allows predictions for mixtures of commonly
used alkali atoms.Comment: 7 pages, 4 figures, uses Revtex 4. This is a companion paper to [PRA
70, 021601(R) (2004)] (cond-mat/0405419
Sub-milliKelvin spatial thermometry of a single Doppler cooled ion in a Paul trap
We report on observations of thermal motion of a single, Doppler-cooled ion
along the axis of a linear radio-frequency quadrupole trap. We show that for a
harmonic potential the thermal occupation of energy levels leads to Gaussian
distribution of the ion's axial position. The dependence of the spatial thermal
spread on the trap potential is used for precise calibration of our imaging
system's point spread function and sub-milliKelvin thermometry. We employ this
technique to investigate the laser detuning dependence of the Doppler
temperature.Comment: 5 pages, 4 figure
Improving voluntary public good provision by a non-governmental, endogenous matching mechanism : experimental evidence
Social norms can help to foster cooperation and to overcome the free-rider problem in private provision of public goods. This paper focuses on the enforcement of social norms by a self-introduced punishment and reward scheme. We analyse if subjects achieve to implement a norm-enforcement mechanism at their own expense by applying the theory of non-governmental norm-enforcement by Buchholz et al. (2014) in a laboratory experiment. Based on their theory without central authority and endogenously determined enforcement mechanism, we implement a two-stage public good game: At the first stage subjects determine the strength of penalty/reward on their own and in the second stage they decide on their contributions to the public good. We find that the mechanism by Buchholz et al. (2014) leads to a higher public good contribution than without the use of any mechanism. Only in a few cases groups end up with a zero enforcement mechanism. This result indicates that subjects are apparently willing to contribute funds for implementing an enforcement mechanism. Moreover, higher enforcement parameters lead to higher public good contributions in the second stage, although too high enforcement parameters lead to unreachable theoretical optima
Reciprocity relations between ordinary temperature and the Frieden-Soffer's Fisher-temperature
Frieden and Soffer conjectured some years ago the existence of a ``Fisher
temperature" T_F that would play, with regards to Fisher's information measure
I, the same role that the ordinary temperature T plays vis-a-vis Shannon's
logarithmic measure. Here we exhibit the existence of reciprocity relations
between T_F and T and provide an interpretation with reference to the meaning
of T_F for the canonical ensemble.Comment: 3 pages, no figure
Programming DNA Tube Circumferences
Synthesizing molecular tubes with monodisperse, programmable circumferences is an important goal shared by nanotechnology, materials science, and supermolecular chemistry. We program molecular tube circumferences by specifying the complementarity relationships between modular domains in a 42-base single-stranded DNA motif. Single-step annealing results in the self-assembly of long tubes displaying monodisperse circumferences of 4, 5, 6, 7, 8, 10, or 20 DNA helices
Thermodynamic cost of reversible computing
Since reversible computing requires preservation of all information
throughout the entire computational process, this implies that all errors that
appear as a result of the interaction of the information-carrying system with
uncontrolled degrees of freedom must be corrected. But this can only be done at
the expense of an increase in the entropy of the environment corresponding to
the dissipation, in the form of heat, of the ``noisy'' part of the system's
energy.
This paper gives an expression of that energy in terms of the effective noise
temperature, and analyzes the relationship between the energy dissipation rate
and the rate of computation. Finally, a generalized Clausius principle based on
the concept of effective temperature is presented.Comment: 5 pages; added two paragraphs and fixed a number of typo
Self-replication and evolution of DNA crystals
Is it possible to create a simple physical system that is capable of replicating itself? Can such a system evolve interesting behaviors, thus allowing it to adapt to a wide range of environments? This paper presents a design for such a replicator constructed exclusively from synthetic DNA. The basis for the replicator is crystal growth: information is stored in the spatial arrangement of monomers and copied from layer to layer by templating. Replication is achieved by fragmentation of crystals, which produces new crystals that carry the same information. Crystal replication avoids intrinsic problems associated with template-directed mechanisms for replication of one-dimensional polymers. A key innovation of our work is that by using programmable DNA tiles as the crystal monomers, we can design crystal growth processes that apply interesting selective pressures to the evolving sequences. While evolution requires that copying occur with high accuracy, we show how to adapt error-correction techniques from algorithmic self-assembly to lower the replication error rate as much as is required
Dynamic roughening and fluctuations of dipolar chains
Nonmagnetic particles in a carrier ferrofluid acquire an effective dipolar
moment when placed in an external magnetic field. This fact leads them to form
chains that will roughen due to Brownian motion when the magnetic field is
decreased. We study this process through experiments, theory and simulations,
three methods that agree on the scaling behavior over 5 orders of magnitude.
The RMS width goes initially as , then as before it
saturates. We show how these results complement existing results on polymer
chains, and how the chain dynamics may be described by a recent non-Markovian
formulation of anomalous diffusion.Comment: 4 pages, 3 figures, submitted to Phys. Rev. Let
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