7,637 research outputs found
Development of the Universe and New Cosmology
Cosmology is undergoing an explosive period of activity, fueled both by new,
accurate astrophysical data and by innovative theoretical developments.
Cosmological parameters such as the total density of the Universe and the rate
of cosmological expansion are being precisely measured for the first time, and
a consistent standard picture of the Universe is beginning to emerge. Recent
developments in cosmology give rise the intriguing possibility that all
structures in the Universe, from superclusters to planets, had a
quantum-mechanical origin in its earliest moments. Furthermore, these ideas are
not idle theorizing, but predictive, and subject to meaningful experimental
test. We review the concordance model of the development of the Universe, as
well as evidence for the observational revolution that this field is going
through. This already provides us with important information on particle
physics, which is inaccessible to accelerators.Comment: 9 pages; The German translation of this mini review can be uploaded
from http://www.cc.ethz.ch/bulletin/ New references are added with respective
minor changes of tex
Spatial and Temporal Analysis of the Morphological and Land use Characteristics of the Buffalo River Watershed
The Buffalo River was established by Congress iQ. 1972 as the first National River in the United States. The Buffalo River, which originates in the higher elevations of the Boston Mountains in Newton County, is one of the few remaining free-flowing streams in Arkansas. It is considered to be one of Arkansas\u27 greatest natural treasures, and thus, there is strong interest in protecting it from anthropogenic influences. An initial characterization of the soil taxonomic units, watershed boundaries, topography and physiographic units in the Buffalo River Watershed was presented by Scott and Smith (1994). The spatial distribution of the geologic units in the watershed was presented by Hofer et al. (1995)
New obstructions to symplectic embeddings
In this paper we establish new restrictions on symplectic embeddings of
certain convex domains into symplectic vector spaces. These restrictions are
stronger than those implied by the Ekeland-Hofer capacities. By refining an
embedding technique due to Guth, we also show that they are sharp.Comment: 80 pages, 3 figures, v2: improved exposition and minor corrections,
v3: Final version, expanded and improved exposition and minor corrections.
The final publication is available at link.springer.co
Spatial Distribution of the Surface Geology and 1992 Land Use of the Buffalo River Watershed
The Buffalo River was established by Congress in 1972 as the first National River in the United States and is one of the few remaining free-flowing streams in Arkansas . The Buffalo River flows through the three major physiographic provinces of northern Arkansas, originating in the higher elevations of the Boston Mountains, and flowing generally northeastward to cut through the Springfield and Salem Plateaus. It drops from approximately 2000 feet in the headwaters to around 500 feet above sea level at its confluence with the White River in Marion County. The Buffalo River is considered to be one of Arkansas\u27 greatest natural treasures; thus there is strong interest in protecting it from undue anthropogenic influences. A general description of the area within the Buffalo River Watershed was given by Smith (1967)
Charge Determination of High Energy Electrons and Nuclei by Synchrotron Radiation with AMS
We investigate the possibilities to identify the charge of TeV electrons and
PeV nuclei using their synchrotron radiation in the earth's magnetic field.
Characteristics of synchrotron radiation photons are evaluated and methods of
detection are discussed.Comment: 9 pages, 6 figure
Global surfaces of section in the planar restricted 3-body problem
The restricted planar three-body problem has a rich history, yet many
unanswered questions still remain. In the present paper we prove the existence
of a global surface of section near the smaller body in a new range of energies
and mass ratios for which the Hill's region still has three connected
components. The approach relies on recent global methods in symplectic geometry
and contrasts sharply with the perturbative methods used until now.Comment: 11 pages, 1 figur
Compactness results in Symplectic Field Theory
This is one in a series of papers devoted to the foundations of
Symplectic Field Theory sketched in [Y Eliashberg, A Givental and H
Hofer, Introduction to Symplectic Field Theory,
Geom. Funct. Anal. Special Volume, Part II (2000) 560--673]. We prove
compactness results for moduli spaces of holomorphic curves arising in
Symplectic Field Theory. The theorems generalize Gromov's compactness theorem
in [M Gromov, Pseudo-holomorphic curves in symplectic manifolds, Invent. Math.
82 (1985) 307--347] as well as compactness theorems in Floer homology theory,
[A Floer, The unregularized gradient flow of the symplectic action, Comm. Pure
Appl. Math. 41 (1988) 775--813 and Morse theory for Lagrangian intersections,
J. Diff. Geom. 28 (1988) 513--547], and in contact geometry, [H Hofer,
Pseudo-holomorphic curves and Weinstein conjecture in dimension three, Invent.
Math. 114 (1993) 307--347 and
H Hofer, K Wysocki and E Zehnder, Foliations of the Tight Three
Sphere, Annals of Mathematics, 157 (2003) 125--255].Comment: Published by Geometry and Topology at
http://www.maths.warwick.ac.uk/gt/GTVol7/paper25.abs.htm
Algebraic Torsion in Contact Manifolds
We extract a nonnegative integer-valued invariant, which we call the "order
of algebraic torsion", from the Symplectic Field Theory of a closed contact
manifold, and show that its finiteness gives obstructions to the existence of
symplectic fillings and exact symplectic cobordisms. A contact manifold has
algebraic torsion of order zero if and only if it is algebraically overtwisted
(i.e. has trivial contact homology), and any contact 3-manifold with positive
Giroux torsion has algebraic torsion of order one (though the converse is not
true). We also construct examples for each nonnegative k of contact 3-manifolds
that have algebraic torsion of order k but not k - 1, and derive consequences
for contact surgeries on such manifolds. The appendix by Michael Hutchings
gives an alternative proof of our cobordism obstructions in dimension three
using a refinement of the contact invariant in Embedded Contact Homology.Comment: 53 pages, 4 figures, with an appendix by Michael Hutchings; v.3 is a
final update to agree with the published paper, and also corrects a minor
error that appeared in the published version of the appendi
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