916 research outputs found
Smooth submanifolds intersecting any analytic curve in a discrete set
We construct examples of smooth submanifolds in and
of codimension 2 and 1, which intersect every complex,
respectively real, analytic curve in a discrete set. The examples are realized
either as compact tori or as properly imbedded Euclidean spaces, and are the
graphs of quasianalytic functions. In the complex case, these submanifolds
contain real -dimensional tori or Euclidean spaces that are not pluripolar
while the intersection with any complex analytic disk is polar
Quasianalyticity and pluripolarity
We show that the graph in
of a function on the unit circle which is either
continuous and quasianalytic in the sense of Bernstein or and
quasianalytic in the sense of Denjoy is pluripolar
Quantum phase diagram of the integrable p_x+ip_y fermionic superfluid
We determine the zero temperature quantum phase diagram of a p_x+ip_y pairing
model based on the exactly solvable hyperbolic Richardson-Gaudin model. We
present analytical and large-scale numerical results for this model. In the
continuum limit, the exact solution exhibits a third-order quantum phase
transition, separating a strong-pairing from a weak-pairing phase. The mean
field solution allows to connect these results to other models with p_x+ip_y
pairing order. We define an experimentally accessible characteristic length
scale, associated with the size of the Cooper pairs, that diverges at the
transition point, indicating that the phase transition is of a
confinement-deconfinement type without local order parameter. We show that this
phase transition is not limited to the p_x+ip_y pairing model, but can be found
in any representation of the hyperbolic Richardson-Gaudin model and is related
to a symmetry that is absent in the rational Richardson-Gaudin model.Comment: 12 figure
Observation of the fine structure for rovibronic spectral lines in visible part of emission spectra of
For the first time in visible part of the emission spectrum the pseudo
doublets representing partly resolved fine structure of rovibronic lines have
been observed. They are characterized by splitting values about 0.2 cm
and relative intensity of the doublet components close to 2.0. It is shown that
they are determined by triplet splitting in lower rovibronic levels of various
electronic transitions. It is proposed to use
an existence of such partly resolved fine structure patterns for identification
of numerous unassigned spectral lines of the molecule coming from great
variety of triplet "gerade" electronic states to vibro-rotational levels of the
state.Comment: 6 pages, including 2 figures and 1 table; submitted to Phys.Rev.Let
Photometric Solutions for Detached Eclipsing Binaries: selection of ideal distance indicators in the SMC
Detached eclipsing binary stars provide a robust one-step distance
determination to nearby galaxies. As a by-product of Galactic microlensing
searches, catalogs of thousands of variable stars including eclipsing binaries
have been produced by the OGLE, MACHO and EROS collaborations. We present
photometric solutions for detached eclipsing binaries in the Small Magellanic
Cloud (SMC) discovered by the OGLE collaboration. The solutions were obtained
with an automated version of the Wilson-Devinney program. By fitting mock
catalogs of eclipsing binaries we find that the normalized stellar radii
(particularly their sum) and the surface brightness ratio are accurately
described by the fitted parameters and estimated standard errors, despite
various systematic uncertainties. In many cases these parameters are well
constrained. In addition we find that systems exhibiting complete eclipses can
be reliably identified where the fractional standard errors in the radii are
small. We present two quantitatively selected sub-samples of eclipsing binaries
that will be excellent distance indicators. These can be used both for
computation of the distance to the SMC and to probe its structure. One
particularly interesting binary has a very well determined solution, exhibits
complete eclipses, and is comprised of well detached G-type, class giants.Comment: 29 pages, 12 figures. To be published in Ap
Disruption of the three-body gravitational systems: Lifetime statistics
We investigate statistics of the decay process in the equal-mass three-body
problem with randomized initial conditions. Contrary to earlier expectations of
similarity with "radioactive decay", the lifetime distributions obtained in our
numerical experiments turn out to be heavy-tailed, i.e. the tails are not
exponential, but algebraic. The computed power-law index for the differential
distribution is within the narrow range, approximately from -1.7 to -1.4,
depending on the virial coefficient. Possible applications of our results to
studies of the dynamics of triple stars known to be at the edge of disruption
are considered.Comment: 13 pages, 2 tables, 3 figure
Non-Equilibrium Surface Diffusion Measurements in Systems with Interactions
Diffusion in surface overlayers with adsorbate-adsorbate interactions is described in terms of coverage-dependent diffusion coefficients. The measured phenomenological Arrhenius parameters (activation energy and prefactor) depend on the initial configuration of the system. Since different experimental methods probe the system in different states, the measured diffusion coefficients depend on the method used. Experimental results demonstrating this dependence are presented for O/W(110) -p(2x1) + p(2x2) and Ag/Si(111) -√3 x √3 R30°. They were measured during the evolution of the system to attain a new equilibrium state of different symmetry. In addition, simulations on lattice gas models with interactions, modeling other surface diffusion techniques (Laser-lnduced-Desorption, fluctuation, non-equilibrium kinetics) support the configuration-dependent results
Urea amidolyase of Candida utilis : Characterization of the urea cleavage reactions
Evidence is presented that the enzymes catalyzing the three reactions involved in urea cleavage in Candida utilis, biotin carboxylation, urea carboxylation, and allophanate hydrolysis occur as a complex of enzymes. The allophanatehydrolyzing activity could not be separated from the urea-cleaving activity using common methods of protein purification. Further, urea cleavage and allophanate hydrolysis activities are induced coordinately in cells grown on various nitrogen sources.The reactions involved in urea cleavage can be distinguished from one another on the basis of their sensitivities to (a) heat, (b) pH, and (c) chemical inhibitors. Evidence is presented for the product of the first reaction in urea cleavage, biotin carboxylation. Production of carboxylated enzyme is ATP dependent and avidin sensitive. Carboxylated enzyme is not observed in the presence of 1 mM urea.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/21726/1/0000118.pd
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