100,026 research outputs found
The Generalized Continuum Hypothesis revisited
We argue that we solved Hilbert's first problem positively (after
reformulating it just to avoid the known consistency results) and give some
applications. Let lambda to the revised power of kappa, denoted
lambda^{[kappa]}, be the minimal cardinality of a family of subsets of lambda
each of cardinality kappa such that any other subset of lambda of cardinality
kappa is included in the union of <kappa members of the family. The main
theorem says that almost always this revised power is equal to lambda. Our main
result is The Revised GCH Theorem:
Assume we fix an uncountable strong limit cardinal mu (i.e., mu>aleph_0, (for
all theta= mu for
some kappa<mu we have:
(a) kappa lambda^{[theta]}= lambda and
(b) there is a family P of lambda subsets of lambda each of cardinality < mu
such that every subset of lambda of cardinality mu is equal to the union of <
kappa members of P
Deciding the Continuum Hypothesis with the Inverse Powerset
We introduce the concept of inverse powerset by adding three axioms to the
Zermelo-Fraenkel set theory. This extends the Zermelo-Fraenkel set theory with
a new type of set which is motivated by an intuitive meaning and interesting
applications. We present different ways to extend the definition of cardinality
and show that one implies the continuum hypothesis while another implies the
negation of the continuum hypothesis. We will also explore the idea of empty
sets of different cardinalities which could be seen as the empty counterpart of
Cantor's theorem for infinite sets.Comment: 37 pages; added and refined a few definition
You Can Enter Cantor's Paradise
This paper is based on the talk given by the author after he received the
International Bolyai Prize in Mathematics (on November 4, 2000 in Budapest,
Hungary)
Multiscale Analysis and Localization of Random Operators
A discussion of the method of multiscale analysis in the study of
localization of random operators based on lectures given at \emph{Random
Schr\"odinger operators: methods, results, and perspectives}, \'Etats de la
recherche, Universit\'e Paris 13, June 200
Topological detection of Lyapunov instability
Given an arbitrary continuous flow on a manifold M, let CMin be the set of
its compact minimal sets, endowed with the Hausdorff metric, and S the subset
of those that are Lyapunov stable. A topological characterization of the
interior of S, the set of Lyapunov stable compact minimal sets that are away
from Lyapunov unstable ones is given, together with a description of the
dynamics around it. In particular, int S is locally a Peano continuum (Peano
curve) and each of its countably many connected components admits a complete
geodesic metric.
This result establishes unexpected connections between the local topology of
CMin and the dynamics of the flow, providing criteria for the local detection
of Lyapunov instability by merely looking at the topology of CMin. For
instance, if CMin is not locally connected at some compact minimal set Q (seen
as a "point" of CMin), then every neighbourhood of Q in M contains Lyapunov
unstable compact minimal sets (hence, if CMin is nowhere locally connected,
then every neighbourhood of each compact minimal set contains infinitely many
Lyapunov unstable compact minimal sets).Comment: Replaces "Lyapunov stability away from instability"; pages 1-3 and
Section 3.1 are new; minor lapses corrected; 29 pages, 7 figures
Generalized measurement on size of set
We generalize the measurement using an expanded concept of cover, in order to
provide a new approach to size of set other than cardinality. The generalized
measurement has application backgrounds such as a generalized problem in
dimension reduction, and has reasons from the existence of the minimum of both
the positive size and the positive graduation, i.e., both the minimum is the
size of the set . The minimum of positive graduation in actual measurement
provides the possibility that an object cannot be partitioned arbitrarily,
e.g., an interval cannot be partitioned by arbitrarily infinite times
to keep compatible with the minimum of positive size. For the measurement on
size of set, it can be assumed that this minimum is the size of , in
symbols or graduation 1. For a set , we generalize any graduation as
the size of a set where , and is
represented by a pair, in symbols , where and
is a set function on , with independent of the order and
reflecting the quantity of . This pair is a generalized form of
box-counting dimension. The yielded size satisfies the properties of outer
measure in general cases, and satisfies the properties of measure in the case
of graduation 1; while in the reverse view, measure is a size using the
graduation of size of an interval. As for cardinality, the yielded size is a
one-to-one correspondence where only addition is allowable, a weak form of
cardinality, and rewrites Continuum Hypothesis using dimension as . In the reverse view, cardinality of a set is a size in the
graduation of the set. The generalized measurement provides a unified approach
to dimension, measure, cardinality and hence infinity.Comment: 10 pages, 0 figures, using amsar
Localization for Anderson Models on Metric and Discrete Tree Graphs
We establish spectral and dynamical localization for several Anderson models
on metric and discrete radial trees. The localization results are obtained on
compact intervals contained in the complement of discrete sets of exceptional
energies. All results are proved under the minimal hypothesis on the type of
disorder: the random variables generating the trees assume at least two
distinct values. This level of generality, in particular, allows us to treat
radial trees with disordered geometry as well as Schr\"odinger operators with
Bernoulli-type singular potentials. Our methods are based on an interplay
between graph-theoretical properties of radial trees and spectral analysis of
the associated random differential and difference operators on the half-line.Comment: 55 pages; several changes to the exposition in v
Saturation and elementary equivalence of C*-algebras
We study the saturation properties of several classes of -algebras.
Saturation has been shown by Farah and Hart to unify the proofs of several
properties of coronas of -unital -algebras; we extend their
results by showing that some coronas of non--unital -algebras are
countably degree- saturated. We then relate saturation of the abelian
-algebra , where is -dimensional, to topological properties
of , particularly the saturation of .Comment: 36 pages. Version 4 is rewritten for clarity in several place
Physical Objects of Dark Systems
The hypothesis of existence of off-site continuums is investigated.
Principles of the physical description are formulated. The structure of
off-site continuums and opportunities of observation of off-site physical
objects from the continuum of the observer is investigated. There are found
conformities between properties of the considered objects with properties of
known physical objects and fundamental interactions both in micro-, and
macro-scales.Comment: LaTeX2e, 11 pages, 2 figure
On \emph{-}weakly universal functions
A function is called
\emph{-weakly universal }if for every function
there is an injective
function and a function such that for every
. We will prove that it is consistent that there are
no \emph{-}weakly universal functions, this
answers a question of Shelah and Stepr\={a}ns. In fact, we will prove that
there are no \emph{-}weakly universal functions in
the Cohen model and after adding Sacks reals side-by-side.
However, we show that there are \emph{-}weakly
universal functions in the Sacks model. In particular, the existence of such
graphs is consistent with and the negation of the Continuum
Hypothesis
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