1,538 research outputs found
TACMB-1: The Theory of Anisotropies in the Cosmic Microwave Background (Bibliographic Resource Letter)
This Resource Letter provides a guide to the literature on the theory of
anisotropies in the cosmic microwave background. Journal articles, web pages,
and books are cited for the following topics: discovery, cosmological origin,
early work, recombination, general CMB anisotropy references, primary CMB
anisotropies (numerical, analytical work), secondary effects,
Sunyaev-Zel'dovich effect(s), lensing, reionization, polarization, gravity
waves, defects, topology, origin of fluctuations, development of fluctuations,
inflation and other ties to particle physics, parameter estimation, recent
constraints, web resources, foregrounds, observations and observational issues,
and gaussianity.Comment: AJP/AAPT Bibliographic Resource letter published Feb. 2002, 24 pages
(9 of text), 1 figur
Combining galaxy and 21cm surveys
Acoustic waves traveling through the early Universe imprint a characteristic
scale in the clustering of galaxies, QSOs and inter-galactic gas. This scale
can be used as a standard ruler to map the expansion history of the Universe, a
technique known as Baryon Acoustic Oscillations (BAO). BAO offer a
high-precision, low-systematics means of constraining our cosmological model.
The statistical power of BAO measurements can be improved if the `smearing' of
the acoustic feature by non-linear structure formation is undone in a process
known as reconstruction. In this paper we use low-order Lagrangian perturbation
theory to study the ability of cm experiments to perform reconstruction
and how augmenting these surveys with galaxy redshift surveys at relatively low
number densities can improve performance. We find that the critical number
density which must be achieved in order to benefit cm surveys is set by
the linear theory power spectrum near its peak, and corresponds to densities
achievable by upcoming surveys of emission line galaxies such as eBOSS and
DESI. As part of this work we analyze reconstruction within the framework of
Lagrangian perturbation theory with local Lagrangian bias, redshift-space
distortions, -dependent noise and anisotropic filtering schemes.Comment: 10 pages, final version to appear in MNRAS, helpful suggestions from
referee and others include
A Comparison of Simulated and Analytic Major Merger Counts
We use large volume, high resolution, N-body simulations of 3 different
CDM models, with different clustering strengths, to generate dark
matter halo merging histories. Over the reliable range of halo masses, roughly
galaxy groups to rich clusters of galaxies, we quantify the number density of
major mergers for two different time intervals and compare with analytic
predictions based on the extended Press-Schechter (1974) theory.Comment: 24 pages, 18 figures. Comments welcome. Final version to appear
MNRAS, helpful suggestions from referee and others incorporate
Constraints on the correlation between QSO luminosity and host halo mass from high-redshift quasar clustering
Recent measurements of high-redshift QSO clustering from the Sloan Digital
Sky Survey indicate that QSOs at z~4 have a bias b~14. We find that this
extremely high clustering amplitude, combined with the corresponding space
density, constrains the dispersion in the L-Mhalo relation to be less than 50%
at 99% confidence for the most conservative case of a 100% duty cycle. This
upper limit to the intrinsic dispersion provides as strong a constraint as
current upper limits to the intrinsic dispersion in the local M_BH-sigma
relation and the ratio of bolometric to Eddington luminosity of luminous QSOs.Comment: 6 pages, 4 figures. Minor revisions to address questions from
referee. References update
Algebras in Higher Dimensional Statistical Mechanics - the Exceptional Partition (MEAN Field) Algebras
We determine the structure of the partition algebra (a generalized
Temperley-Lieb algebra) for specific values of Q \in \C, focusing on the
quotient which gives rise to the partition function of site -state Potts
models (in the continuous formulation) in arbitrarily high lattice
dimensions (the mean field case). The algebra is non-semi-simple iff is a
non-negative integer less than . We determine the dimension of the key
irreducible representation in every specialization.Comment: 4 page
Heat Conduction and Magnetic Phase Behavior in Electron-Doped Ca_{1-x} La_x MnO_3(0 <= x <= 0.2)
Measurements of thermal conductivity (kappa) vs temperature are reported for
a series of Ca_{1-x} La_x MnO_3(0 <= x <= 0.2) specimens. For the undoped
(x=0), G-type antiferromagnetic compound a large enhancement of kappa below the
Neel temperature (T_N ~ 125 K) indicates a strong coupling of heat-carrying
phonons to the spin system. This enhancement exhibits a nonmonotonic behavior
with increasing x and correlates remarkably well with the small ferromagnetic
component of the magnetization reported previously [Neumeier and Cohn, Phys.
Rev. B 61 14319 (2000).] Magnetoelastic polaron formation appears to underly
the behavior of kappa and the magnetization at x <= 0.02.Comment: submitted to PRB; 4 pp., 4 Fig.'s, RevTex
Multidisciplinary team meetings in palliative care: an ethnographic study
OBJECTIVES: Multidisciplinary team meetings are a regular feature in the provision of palliative care, involving a range of professionals. Yet, their purpose and best format are not necessarily well understood or documented. This article describes how hospital and community-based palliative care multidisciplinary team meetings operate to elucidate some of their main values and offer an opportunity to share examples of good practice. METHODS: Ethnographic observations of over 70 multidisciplinary team meetings between May 2018 and January 2020 in hospital and community palliative care settings in intercity London. These observations were part of a larger study examining palliative care processes. Fieldnotes were thematically analysed. RESULTS: This article analyses how the meetings operated in terms of their setup, participants and general order of business. Meetings provided a space where patients, families and professionals could be cared for through regular discussions of service provision. CONCLUSIONS: Meetings served a variety of functions. Alongside discussing the more technical, clinical and practical aspects that are formally recognised aspects of the meetings, an additional core value was enabling affectual aspects of dealing with people who are dying to be acknowledged and processed collectively. Insight into how the meetings are structured and operate offer input for future practice
The Blob Algebra and the Periodic Temperley-Lieb Algebra
We determine the structure of two variations on the Temperley-Lieb algebra,
both used for dealing with special kinds of boundary conditions in statistical
mechanics models.
The first is a new algebra, the `blob' algebra (the reason for the name will
become obvious shortly!). We determine both the generic and all the exceptional
structures for this two parameter algebra. The second is the periodic
Temperley-Lieb algebra. The generic structure and part of the exceptional
structure of this algebra have already been studied. Here we complete the
analysis, using results from the study of the blob algebra.Comment: 12 page
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