46,695 research outputs found
High Redshift Standard Candles: Predicted Cosmological Constraints
We investigate whether future measurements of high redshift standard candles
(HzSCs) will be a powerful probe of dark energy, when compared to other types
of planned dark energy measurements. Active galactic nuclei and gamma ray
bursts have both been proposed as potential HzSC candidates. Due to their high
luminosity, they can be used to probe unexplored regions in the expansion
history of the universe. Information from these regions can help constrain the
properties of dark energy, and in particular, whether it varies over time.
We consider both linear and piecewise parameterizations of the dark energy
equation of state, , and assess the optimal redshift distribution a
high-redshift standard-candle survey could take to constrain these models.
The more general the form of the dark energy equation of state being
tested, the more useful high-redshift standard candles become. For a linear
parameterization of , HzSCs give only small improvements over planned
supernova and baryon acoustic oscillation measurements; a wide redshift range
with many low redshift points is optimal to constrain this linear model.
However to constrain a general, and thus potentially more informative, form of
, having many HzSCs can significantly improve limits on the nature of
dark energy.Comment: Accepted MNRAS, 27 Pages, 15 figures, matches published versio
Seasonal variations in Greenland Ice Sheet motion : Inland extent and behaviour at higher elevations
Peer reviewedPreprin
String-Inspired Triplet See-Saw from Diagonal Embedding of SU(2)_L in SU(2)_A x SU(2)_B
Motivated by string constructions, we consider a variant on the Type II
see-saw mechanism involving the exchange of triplet representations of SU(2)_L
in which this group arises from a diagonal embedding into SU(2)_A x SU(2)_B. A
natural assignment of Standard Model lepton doublets to the two underlying
gauge groups results in a bimaximal pattern of neutrino mixings and an inverted
hierarchy in masses. Simple perturbations around this leading-order structure
can accommodate the observed pattern of neutrino masses and mixings.Comment: 8 pages; uses RevTe
Doing it differently: Engaging interview participants with imaginative variation
Imaginative variation was identified by Husserl (1936/1970) as a phenomenological technique for the purpose of elucidating the manner in which phenomena appear to consciousness. Briefly, by engaging in the phenomenological reduction and using imaginative variation, phenomenologists are able to describe the experience of consciousness, having stepped outside of the natural attitude through the epochÄ. Imaginative variation is a stage aimed at explicating the structures of experience, and is best described as a mental experiment. Features of the experience are imaginatively altered in order to view the phenomenon under investigation from varying perspectives. Husserl argued that this process will reveal the essences of an experience, as only those aspects that are invariant to the experience of the phenomenon will not be able to change through the variation.
Often in qualitative research interviews, participants struggle to articulate or verbalise their experiences. The purpose of this article is to detail a radical and novel way of using imaginative variation with interview participants, by asking the participants to engage with imaginative variation, in order to produce a rich and insightful experiential account of a phenomenon. We will discuss how the first author successfully used imaginative variation in this way in her study of the erotic experience of bondage, discipline, dominance & submission, and sadism & masochism (BDSM), before considering the usefulness of this technique when applied to areas of study beyond sexuality
Revealing the Archetype: The Journey of a Trecento Madonna and Child at the National Museum of Scotland
The National Museums Scotland Madonna and
Child project sought to uncover and document
the history of a fine polychrome wood carving
attributed to The Master of the Gualino St
Catherine and to prepare it for display. A new
body of knowledge has been assembled by
the interdisciplinary team. The conservation
treatment was informed by this work and led
to further discoveries: the removal of overpaint
exposing a previously hidden underdrawing.
The ethics of the treatment decisions, including
the removal of the Christ Childâs 1960sâ fingers required team dialogue and was opened up for
the public to respond to in a series of blogs.
The discovery of a rich polychromy including
gold and glazed tin has led to further plans to
produce a 3-D colour reconstruction. The collaborations
developed during this project will
facilitate future joint ventures for polychrome
sculpture in Scottish collections
Ortho-para transition rate in -molecular hydrogen and the proton's induced pseudoscalar coupling
We report a measurement of the ortho-para transition rate in the pp
molecule. The experiment was conducted at TRIUMF via the measurement of the
time dependence of the 5.2 MeV neutrons from muon capture in liquid hydrogen.
The measurement yielded an ortho-para rate s that is substantially larger than the
earlier result of Bardin {\it et al.} We discuss the striking implications for
the proton's induced pseudoscalar coupling .Comment: 4 pages, 3 figures, submitted to Phys. Rev. Let
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