15,393 research outputs found
Oscillation parameters present: Session summary
© Copyright owned by the author(s) under the terms of the Creative Commons. Session I of the Neutrino Oscillation Workshop 2018 Conference, âNeutrino Oscillations: Presentâ, is summarised. Results were presented by the currently-running long-baseline oscillation experiments T2K and NOvA, as well as from the accelerator experiments OPERA and MiniBooNE. Status reports and results from experiments using short-baseline accelerator neutrinos (ICARUS and MicroBooNE), atmospheric neutrinos (Super-K, IceCube and ANTARES), and those from reactors (Daya Bay and Double Chooz), and from the Sun and the Earth (Borexino) were also presented. Our current knowledge of neutrino oscillation parameters depends significantly on the experimental inputs that inform us of details of the production and interactions of neutrinos, which were presented by the NA61/SHINE hadron production experiment and cross section measurements from T2K and MINERvA, as well as a review of the status of our understanding of neutrino production at nuclear reactors. The session also included theoretical reviews of the current status of neutrino oscillations, and phenomenological studies on neutrino tomography and experimental studies to support nuclear matrix element calculations (NUMEN)
The PPP hypothesis revisited: Evidence using a multivariate long-memory model
This paper examines the PPP hypothesis analysing the behaviour of the real exchange rates vis-Ă -vis the US dollar for four major currencies (namely, the Canadian dollar, the euro, the Japanese yen and the British pound). An innovative approach based on fractional integration in a multivariate context is applied to annual data from 1970 to 2011. Long memory is found to characterise the Canadian dollar, the British pound and the euro, but in all four cases the results are consistent with the relative version of PPP
Discovery of a remarkable subpulse drift pattern in PSR B0818-41
We report the discovery of a remarkable subpulse drift pattern in the
relatively less studied wide profile pulsar, B0818-41, using high sensitivity
GMRT observations. We find simultaneous occurrence of three drift regions with
two different drift rates: an inner region with steeper apparent drift rate
flanked on each side by a region of slower apparent drift rate. Furthermore,
these closely spaced drift bands always maintain a constant phase relationship.
Though these drift regions have significantly different values for the measured
P2, the measured P3 value is the same and equal to 18.3 P1. We interpret the
unique drift pattern of this pulsar as being created by the intersection of our
line of sight (LOS) with two conal rings on the polar cap of a fairly aligned
rotator (inclination angle alpha ~ 11 deg), with an ``inner'' LOS geometry
(impact angle beta ~ -5.4 deg). We argue that both the rings have the same
values for the carousel rotation periodicity P4 and the number of sparks Nsp.
We find that Nsp is 19-21 and show that it is very likely that, P4 is the same
as the measured P3, making it a truly unique pulsar. We present results from
simulations of the radiation pattern using the inferred parameters, that
support our interpretations and reproduce the average profile as well as the
observed features in the drift pattern quite well.Comment: 5 pages and 7 figures, Accepted for publication in MNRAS Letter
Requirements for Provenance on the Web
From where did this tweet originate? Was this quote from the New York Times modified? Daily, we rely on data from the Web but often it is difficult or impossible to determine where it came from or how it was produced. This lack of provenance is particularly evident when people and systems deal with Web information or with any environment where information comes from sources of varying quality. Provenance is not captured pervasively in information systems. There are major technical, social, and economic impediments that stand in the way of using provenance effectively. This paper synthesizes requirements for provenance on the Web for a number of dimensions focusing on three key aspects of provenance: the content of provenance, the management of provenance records, and the uses of provenance information. To illustrate these requirements, we use three synthesized scenarios that encompass provenance problems faced by Web users toda
Symmetric-Gapped Surface States of Fractional Topological Insulators
We construct the symmetric-gapped surface states of a fractional topological
insulator with electromagnetic -angle and
a discrete gauge field. They are the proper generalizations of
the T-pfaffian state and pfaffian/anti-semion state and feature an extended
periodicity compared with their of "integer" topological band insulators
counterparts. We demonstrate that the surface states have the correct anomalies
associated with time-reversal symmetry and charge conservation.Comment: 5 pages, 33 references and 2 pages of supplemental materia
Unraveling the drift behaviour of the remarkable pulsar PSR B0826-34
We present new results from high sensitivity GMRT observations of PSR
B0826-34. We provide a model to explain the observed subpulse drift properties
of this pulsar, including the apparent reversals of the drift direction. In
this model, PSR B0826-34 is close to being an aligned rotator. We solve for the
emission geometry of this pulsar and show that the angle between the rotation
and the magnetic axes is less than 5 deg. We see evidence for as many as 6 to 7
drifting bands in the main pulse at 318 MHz, which are part of a circulating
system of about 15 spark-associated subpulse emission beams. We provide
quantitative treatments of the aliasing problem and various effects of
geometry. The observed drift rate is an aliased version of the true drift rate,
such that a subpulse drifts to the location of the adjacent subpulse (or a
multiple thereof) in about one pulsar period. We show that small variations, of
the order of 3-8%, in the mean drift rate are then enough to explain the
apparent reversals of drift direction. We find the mean circulation time of the
drift pattern to be significantly longer than the predictions of the original
RS75 model and propose an explanation for this, based on modified models with
temperature regulated partial ion flow in the polar vacuum gap. From the
variation of the mean subpulse separation across the main pulse window, we show
that the spark pattern is not centred around the dipole axis, but around a
point much closer (within a degree or so) to the rotation axis -- we discuss
the implication of this.Comment: 23 pages (including 9 figure). Submitted to Astronomy and
Astrophysics on November 11, 200
Frequency dependence of pulsar radiation patterns
We report on new results from simultaneous, dual frequency, single pulse
observation of PSR B0329+54 using the Giant Metrewave Radio Telescope. We find
that the longitude separation of subpulses at two different frequencies (238
and 612 MHz) is less than that for the corresponding components in the average
profile. A similar behaviour has been noticed before in a number of pulsars. We
argue that subpulses are emitted within narrow flux tubes of the dipolar field
lines and that the mean pulsar beam has a conal structure. In such a model the
longitudes of profile components are determined by the intersection of the line
of sight trajectory with subpulse-associated emission beams. Thus, we show that
the difference in the frequency dependence of subpulse and profile component
longitudes is a natural property of the conal model of pulsar emission beam. We
support our conclusions by numerical modelling of pulsar emission, using the
known parameters for this pulsar, which produce results that agree very well
with our dual frequency observations.Comment: 24 pages, 8 figures. Accepted for publication in Ap
An Empirical Connection between the UV Color of Early Type Galaxies and the Stellar Initial Mass Function
Using new UV magnitudes for a sample of early-type galaxies, ETGs, with
published stellar mass-to-light ratios, Upsilon_*, we find a correlation
between UV color and Upsilon_* that is tighter than those previously identified
between Upsilon_* and either the central stellar velocity dispersion,
metallicity, or alpha enhancement. The sense of the correlation is that
galaxies with larger Upsilon_* are bluer in the UV. We conjecture that
differences in the lower mass end of the stellar initial mass function, IMF,
are related to the nature of the extreme horizontal branch populations that are
generally responsible for the UV flux in ETGs. If so, then UV color can be used
to identify ETGs with particular IMF properties and to estimate Upsilon_*.Comment: Submitted for publication in ApJ Letter
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