114 research outputs found
Remarks on hard Lefschetz conjectures on Chow groups
We propose two conjectures of Hard Lefschetz type on Chow groups and prove
them for some special cases. For abelian varieties, we shall show they are
equivalent to well-known conjectures of Beauville and Murre.Comment: to appear in Sciences in China, Ser. A Mathematic
Cohomological Hasse principle and motivic cohomology for arithmetic schemes
In 1985 Kazuya Kato formulated a fascinating framework of conjectures which
generalizes the Hasse principle for the Brauer group of a global field to the
so-called cohomological Hasse principle for an arithmetic scheme. In this paper
we prove the prime-to-characteristic part of the cohomological Hasse principle.
We also explain its implications on finiteness of motivic cohomology and
special values of zeta functions.Comment: 47 pages, final versio
On Damage Spreading Transitions
We study the damage spreading transition in a generic one-dimensional
stochastic cellular automata with two inputs (Domany-Kinzel model) Using an
original formalism for the description of the microscopic dynamics of the
model, we are able to show analitically that the evolution of the damage
between two systems driven by the same noise has the same structure of a
directed percolation problem. By means of a mean field approximation, we map
the density phase transition into the damage phase transition, obtaining a
reliable phase diagram. We extend this analysis to all symmetric cellular
automata with two inputs, including the Ising model with heath-bath dynamics.Comment: 12 pages LaTeX, 2 PostScript figures, tar+gzip+u
A Class of Topological Actions
We review definitions of generalized parallel transports in terms of
Cheeger-Simons differential characters. Integration formulae are given in terms
of Deligne-Beilinson cohomology classes. These representations of parallel
transport can be extended to situations involving distributions as is
appropriate in the context of quantized fields.Comment: 41 pages, no figure
Galois sections for abelianized fundamental groups
Given a smooth projective curve of genus at least 2 over a number field
, Grothendieck's Section Conjecture predicts that the canonical projection
from the \'etale fundamental group of onto the absolute Galois group of
has a section if and only if the curve has a rational point. We show that there
exist curves where the above map has a section over each completion of but
not over . In the appendix Victor Flynn gives explicit examples in genus 2.
Our result is a consequence of a more general investigation of the existence
of sections for the projection of the \'etale fundamental group `with
abelianized geometric part' onto the Galois group. We give a criterion for the
existence of sections in arbitrary dimension and over arbitrary perfect fields,
and then study the case of curves over local and global fields more closely. We
also point out the relation to the elementary obstruction of
Colliot-Th\'el\`ene and Sansuc.Comment: This is the published version, except for a characteristic 0
assumption added in Section 5 which was unfortunately omitted there. Thanks
to O. Wittenberg for noticing i
Noncommutative Geometry in the Framework of Differential Graded Categories
In this survey article we discuss a framework of noncommutative geometry with
differential graded categories as models for spaces. We outline a construction
of the category of noncommutative spaces and also include a discussion on
noncommutative motives. We propose a motivic measure with values in a motivic
ring. This enables us to introduce certain zeta functions of noncommutative
spaces.Comment: 19 pages. Minor corrections and one reference added; to appear in the
proceedings volume of AGAQ Istanbul, 200
Level of performance of independent nursing functions by staff nurses in selected hospitals in Cavite
This study used a non-experimental descriptive method of research. Using purposive sampling technique, the respondents consisted of staff nurses in selected hospitals in Cavite. The data gathering instrument was a questionnaire, which was adapted from an undergraduate thesis by De Villa, Salazar and Sevilla (2001) entitled “The performance status of community health nurses functions in selected municipalities in Cavite” and was modified accordingly. The statistical treatments utilized were frequency, percentage, f-test or ANOVA and t-test. The study concluded that, 1) Majority of the respondents were 24-27 years old, female, single, had more than one (1) year of experience, had handled more than 10 patients and had monthly income of P10,000 and below; 2) The overall mean level of performance of independent nursing functions by staff nurses was 4.35. This indicates that the nurses perform their independent nursing functions in a moderate extent; 3) The level of performance of independent nursing functions of staff nurses was not significantly related to age, gender, civil status, length of experience and monthly income; 4) The level of performance of independent nursing functions by staff nurses was significantly related to nurse to patient ratio; 5) There was a significant difference in the level of performance of independent nursing functions by staff nurses when grouped according to nurse to patient ratio
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