611 research outputs found
Superdiffusion in a class of networks with marginal long-range connections
A class of cubic networks composed of a regular one-dimensional lattice and a
set of long-range links is introduced. Networks parametrized by a positive
integer k are constructed by starting from a one-dimensional lattice and
iteratively connecting each site of degree 2 with a th neighboring site of
degree 2. Specifying the way pairs of sites to be connected are selected,
various random and regular networks are defined, all of which have a power-law
edge-length distribution of the form with the marginal
exponent s=1. In all these networks, lengths of shortest paths grow as a power
of the distance and random walk is super-diffusive. Applying a renormalization
group method, the corresponding shortest-path dimensions and random-walk
dimensions are calculated exactly for k=1 networks and for k=2 regular
networks; in other cases, they are estimated by numerical methods. Although,
s=1 holds for all representatives of this class, the above quantities are found
to depend on the details of the structure of networks controlled by k and other
parameters.Comment: 10 pages, 9 figure
What makes a space have large weight?
We formulate several conditions (two of them are necessary and sufficient)
which imply that a space of small character has large weight. In section 3 we
construct a ZFC example of a first countable 0-dimensional space X of size
2^omega with w(X)=2^omega and nw(X)=omega, we show that CH implies the
existence of a 0-dimensional space Y of size omega_1 with w(Y)=nw(Y)=omega_1
and chi(Y)=R(Y)=omega, and we prove that it is consistent that 2^omega is as
large as you wish and there is a 0-dimensional space Z of size 2^omega such
that w(Z)=nw(Z)=2^omega but chi(Z)=R(Z^omega)=omega
On the family of B-spline surfaces obtained by knot modification
B-spline surfaces are piecewisely defined surfaces where the section points of the domain of definition are called knots. In [2] the authors proved some theorems in terms of knot modification of B-spline curves. Here we generalize these results for one- and two-parameter family of surfaces. An additional result concerning a higher order contact of these surfaces and an envelope is also proved
On the family of B-spline surfaces obtained by knot modification
B-spline surfaces are piecewisely defined surfaces where the section points of the domain of definition are called knots. In [2] the authors proved some theorems in terms of knot modification of B-spline curves. Here we generalize these results for one- and two-parameter family of surfaces. An additional result concerning a higher order contact of these surfaces and an envelope is also proved
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