Articles
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11/30/2004--
11/30/2004
Probing Halos with PNe: Mass and Angular Momentum in Early-Type Galaxies
We present an observational survey program using planetary nebulae, globular
clusters, and X-ray emission to probe the halos of early-type galaxies. We
review evidence for scanty dark matter halos around ordinary elliptical
galaxies, and discuss the possible implications. We also present measurements
of rotation in the halos.
Aaron J. Romanowsky
04/01/2013--
04/01/2013
The decay of the Walsh coefficients of smooth functions
We give upper bounds on the Walsh coefficients of functions for which the
derivative of order at least one has bounded variation of fractional order.
Further, we also consider the Walsh coefficients of functions in periodic and
non-periodic reproducing kernel Hilbert spaces. A lower bound which shows that
our results are best possible is also shown.
Josef Dick
01/20/2017--
12/24/2015
On the universal function for weighted spaces L^p_u[0,1], p>=1
In the paper it is shown that there exist a function g from L1[0,1] and a
weight function 0<u(x)<=1, so that g is universal for each classes L^p_u[0,1],
p>= 1 with respect to signs-subseries of its Fourier-Walsh series.
Martin Grigoryan
Tigran Grigoryan
Artsrun Sargsyan
01/19/2010--
01/19/2010
Mopra line survey mapping of NGC6334I and I(N) at 3mm
A 5'x5' region encompassing NGC6334I and I(N) has been mapped at a wavelength
of 3mm (from 83.5 to 115.5GHz) with the Mopra telescope at an angular
resolution between 33 arcsec and 36 arcsec. This investigation has made use of
the recently installed 3mm MMIC receiver and the Mopra Spectrometer (MOPS) with
broadband capabilities permitting total coverage of the entire frequency range
with just five different observations. In total, the spatial distribution of
nineteen different molecules, ions and radicals, along with additional selected
isotopologues have been studied. Whilst most species trace the sites of star
formation, CH_3CN appears to be most closely associated with NGC6334I and I(N).
Both CN and C_2H appear to be widespread, tracing gas that is not associated
with active star formation. Both N_2H^+ and HC_3N closely resemble dust
continuum emission, showing they are reliable tracers of dense material, as
well as the youngest stages of high mass star formation. Hot (E_u/k>100K)
thermal CH_3OH emission is preferentially found towards NGC6334I, contrasting
with I(N), where only cold (E_u/k<22K) thermal CH_3OH emission is found.
A. J. Walsh
S. Thorwirth
H. Beuther
M. G. Burton
08/01/2022--
08/01/2022
CP-violation search with T2K data
The T2K experiment is a long-baseline neutrino oscillation experiment which
uses $\nu_{\mu}$ and $\bar{\nu}_{\mu}$ beams to constrain CP-violating effects
in a 3-flavor PMNS neutrino mixing model. Through $\nu_{\mu}\to\nu_{e}$ and
$\bar{\nu}_{\mu}\to\bar{\nu}_{e}$ appearance channels, T2K is sensitive to
CP-violating effects in neutrino mixing. An excess of $\nu_{e}$ candidates in
the $\nu$-beam mode is observed when compared to the CP conserving cases. T2K
finds a best fit value of $\delta_{\mathrm{CP}}=-1.97_{-0.70}^{+0.97}$ using
Feldman-Cousins corrected intervals and excludes CP-conserving values of
$\delta_{\mathrm{CP}}$ of $0$ and $\pi$ at the 90% CL. $J_{\mathrm{CP}}=0$ is
also excluded at 2$\sigma$ when using a flat prior in $\delta_{\mathrm{CP}}$,
favoring negative values.
J. G. Walsh
10/03/2024--
10/03/2024
A Foundation Model for the Solar Dynamics Observatory
SDO-FM is a foundation model using data from NASA's Solar Dynamics
Observatory (SDO) spacecraft; integrating three separate instruments to
encapsulate the Sun's complex physical interactions into a multi-modal
embedding space. This model can be used to streamline scientific investigations
involving SDO by making the enormous datasets more computationally accessible
for heliophysics research and enable investigations that require instrument
fusion. We discuss four key components: an ingestion pipeline to create machine
learning ready datasets, the model architecture and training approach,
resultant embeddings and fine-tunable models, and finally downstream fine-tuned
applications. A key component of this effort has been to include subject matter
specialists at each stage of development; reviewing the scientific value and
providing guidance for model architecture, dataset, and training paradigm
decisions. This paper marks release of our pretrained models and embedding
datasets, available to the community on Hugging Face and sdofm.org.
James Walsh
Daniel G. Gass
Raul Ramos Pollan
Paul J. Wright
Richard Galvez
Noah Kasmanoff
Jason Naradowsky
Anne Spalding
James Parr
Atılım Güneş Baydin
02/09/2019--
02/09/2019
On the Partial Sums and Marcinkiewicz and Fejér Means on the One- and Two-dimensional One-parameter Martingale Hardy Spaces
In this PhD thesis we are dealing with convergence and summability of partial
sums, Fej\'er and Marcinkiewicz means with respect to one- and two-dimensional
Walsh-Fourier series on the martingale Hardy spaces. This thesis is focus to
achieve the following main results: To find estimation of convergence and
divergence of the subsequences of partial sums of the one-dimensional
Walsh-Fourier series on the martingale Hardy spaces $H_p(G)$, when $0<p\leq1$.
To find necessary and sufficient conditions in terms of modulus of continuity
of martingale Hardy spaces, for which subsequences of partial sums of the
one-dimensional Walsh-Fourier series convergence in $H_p(G)$ norm, when
$0<p\leq1$. To find estimation of convergence and divergence of the
subsequences of Fej\'er means of the one-dimensional Walsh-Fourier series on
the martingale Hardy spaces $H_p(G)$, when $0<p\leq1/2$. To find necessary and
sufficient conditions in terms of modulus of continuity of martingale Hardy
spaces, for which subsequences of Fej\'er means of the one-dimensional
Walsh-Fourier series converge in $H_{p}(G)$ norm, when $0<p\leq1/2$. To prove
strong convergence of one-dimensional Fej\'er means with respect to Walsh
system on the martingale Hardy spaces $H_{p}(G)$, when $0<p\leq 1/2$. To prove
strong convergence of diagonal partial sums with respect to the two-dimensional
Walsh-Fourier series on the martingale Hardy spaces $H_{p}(G^2)$, when $0<p<1$.
To prove strong convergence of Marcinkiewicz means with respect to the
two-dimensional Walsh-Fourier series in $H_{2/3}(G^2)$ norm. To find necessary
and sufficient conditions in terms of modulus of continuity of Hardy spaces,
for which Marcinkiewicz means of the two-dimensional Walsh-Fourier series
converge in $H_{2/3}(G^2)$ norm.
George Tephnadze
02/11/2020--
02/11/2020
Some Inequalities Related to Strong Convergence of Riesz Logarithmic Means
In this paper we derive a new strong convergence theorem of Riesz logarithmic
means of the one-dimensional Vilenkin-Fourier (Walsh-Fourier) series. The
corresponding inequality is pointed out and it is also proved that the
inequality is in a sense sharp, at least for the case with Walsh-Fourier
series.
D. Lukkassen
L. E. Persson
G. Tephnadze
G. Tutberidze
02/07/2000--
02/07/2000
Detection of deuterium Balmer lines in the Orion Nebula
The detection and first identification of the deuterium Balmer emission
lines, D-alpha and D-beta, in the core of the Orion Nebula is reported.
Observations were conducted at the 3.6m Canada-France-Hawaii Telescope, using
the Echelle spectrograph Gecko. These lines are very narrow and have identical
11 km/s velocity shifts with respect to H-alpha and H-beta. They are probably
excited by UV continuum fluorescence from the Lyman (DI) lines and arise from
the interface between the HII region and the molecular cloud.
G. Hebrard
D. Pequignot
A. Vidal-Madjar
J. R. Walsh
R. Ferlet
02/02/2005--
02/02/2005
Modelling Kinematics and Dark Matter: The Halos of Elliptical Galaxies
This review is focussed on the outer halos of elliptical galaxies. Its
emphasis is on (i) planetary nebulae as test particles to trace the stellar
kinematics at large radii, (ii) the observed angular momentum in elliptical
galaxy halos and its theoretical relevance, (iii) dynamical modelling of
stellar-kinematic data, and (iv) a discussion of the evidence for dark matter
halos in ellipticals from a wide range of measurements.
Ortwin Gerhard
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