426 research outputs found
More Set-theory around the weak Freese-Nation property
In this paper, we introduce a very weak square principle which is even weaker
than the similar principle introduced by Foreman and Magidor. A
characterization of this principle is given in term of sequences of elementary
submodels of H(\chi). This is used in turn to prove a characterization of
kappa-Freese-Nation property under the very weak square principle and a weak
variant of the Singular Cardinals Hypothesis.
A typical application of this characterization shows that under
2^{\aleph_0}<\aleph_\omega and our very weak square for \aleph_\omega, the
partial ordering [omega_\omega]^{<\omega} (ordered by inclusion) has the
aleph_1-Freese-Nation property.
On the other hand we show that, under Chang's Conjecture for \aleph_\omega
the partial ordering above does not have the aleph_1-Freese-Nation property.
Hence we obtain the independence of our characterization of the
kappa-Freese-Nation property and also of the very weak square principle from
ZFC
The New Hampshire, Vol. 33, No. 10 (Dec. 16, 1942)
An independent student produced newspaper from the University of New Hampshire
The BG News April 12, 1989
The BGSU campus student newspaper April 12, 1989. Volume 71 - Issue 117https://scholarworks.bgsu.edu/bg-news/5931/thumbnail.jp
The Chronicle [March 30, 2009]
The Chronicle, March 30, 2009https://repository.stcloudstate.edu/chron/1703/thumbnail.jp
Visible and dark matter from a first-order phase transition in a baryon-symmetric universe
The similar cosmological abundances observed for visible and dark matter
suggest a common origin for both. By viewing the dark matter density as a
dark-sector asymmetry, mirroring the situation in the visible sector, we show
that the visible and dark matter asymmetries may have arisen simultaneously
through a first-order phase transition in the early universe. The dark
asymmetry can then be equal and opposite to the usual visible matter asymmetry,
leading to a universe that is symmetric with respect to a generalised baryon
number. We present both a general structure, and a precisely defined example of
a viable model of this type. In that example, the dark matter is atomic as well
as asymmetric, and various cosmological and astrophysical constraints are
derived. Testable consequences for colliders include a Z' boson that couples
through the B-L charge to the visible sector, but also decays invisibly to dark
sector particles. The additional scalar particles in the theory can mix with
the standard Higgs boson and provide other striking signatures.Comment: 26 pages, comments and references added, JCAP versio
String Cosmology - Large-Field Inflation in String Theory
This is a short review of string cosmology. We wish to connect string-scale
physics as closely as possible to observables accessible to current or
near-future experiments. Our possible best hope to do so is a description of
inflation in string theory. The energy scale of inflation can be as high as
that of Grand Unification (GUT). If this is the case, this is the closest we
can possibly get in energy scales to string-scale physics. Hence, GUT-scale
inflation may be our best candidate phenomenon to preserve traces of
string-scale dynamics. Our chance to look for such traces is the primordial
gravitational wave, or tensor mode signal produced during inflation. For
GUT-scale inflation this is strong enough to be potentially visible as a B-mode
polarization of the cosmic microwave background (CMB). Moreover, a GUT-scale
inflation model has a trans-Planckian excursion of the inflaton scalar field
during the observable amount of inflation. Such large-field models of inflation
have a clear need for symmetry protection against quantum corrections. This
makes them ideal candidates for a description in a candidate fundamental theory
like string theory. At the same time the need of large-field inflation models
for UV completion makes them particularly susceptible to preserve imprints of
their string-scale dynamics in the inflationary observables, the spectral index
and the fractional tensor mode power . Hence, we will focus this
review on axion monodromy inflation as a mechanism of large-field inflation in
string theory.Comment: 34 pages, 1 figure, LaTeX, v2: typos fixed, 3 references added,
agrees with published version in "Perspectives in String Phenomenology" and
"International Journal of Modern Physics A
The Montana Kaimin, November 30, 1937
Student newspaper of the University of Montana, Missoula.https://scholarworks.umt.edu/studentnewspaper/2667/thumbnail.jp
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