5,566 research outputs found
On the kinematics of the Local cosmic void
We collected the existing data on the distances and radial velocities of
galaxies around the Local Void in the Aquila/Hercules to examine the peculiar
velocity field induced by its underdensity. A sample of 1056 galaxies with
distances measured from the Tip of the Red Giant Branch, the Cepheid
luminosity, the SNIa luminosity, the surface brightness fluctuation method, and
the Tully-Fisher relation has been used for this purpose. The amplitude of
outflow is found to be ~300 km/s. The galaxies located within the void produce
the mean intra-void number density about 1/5 of the mean external number
density of galaxies. The void's population has a lower luminosity and a later
morphological type with the medians: M_B = -15.7^m and T = 8 (Sdm),
respectively.Comment: Version 1. 14 pages, 8 figures, 2 tables. Accepted to Astrophysics,
Volume 54, Issue
Generating Neutrino Mass in the 331 Model
A mechanism for generating small tree-level Majorana mass for neutrinos is
implemented in the 331 Model. No additional fermions or scalars need to be
added, and no mass scale greater than a few TeV is invoked.Comment: LaTex, 7 pages, no figures. Revised version to appear in Phys. Rev.
âWhen I look at this van, itâs not only a vanâ: symbolic objects in the policing of migration
The âGo Home Vanâ was the centrepiece of the UK governmentâs 2013 immigration enforcement campaign. Vehicles were driven around ethnically diverse London neighbourhoods clad with giant posters offering irregular migrants a choice between âvoluntary departureâ and criminal arrest. Abandoned shortly afterwards in response to complaints, the GHV nonetheless had a significant impact on migrants. Through interviews and focus groups, this article investigates what was conveyed by the van, and the means by which it achieved these effects. We find that the GHV communicated meanings about the illegitimacy and criminality of migrants, with its material characteristics (visibility and mobility) as important as the words and pictures on its surface. Migrants sought to resist the van through hiding, while support organisations rejected dominant meanings and crafted alternatives. The article establishes a research agenda around the wider role of symbolic objects, in the context of the global migration crisis
The Interplay between Neutrinos and Charged Leptons in the Minimal SU(3)_LxU(1)_N Gauge Model
In the minimal SU(3)_LxU(1)_N gauge model with a global L_e-L_mu-L_tau (=L')
symmetry and a discrete Z_4 symmetry, it is found that the interplay between
neutrinos and charged leptons contained in triplets of \psi^i=(\nu^i_L,
\ell^i_L, \ell^{ci}_L) (i=1,2,3) naturally leads to the large mixing angle
(LMA) MSW solution. The model includes two (anti)sextet Higgs scalars, S^(0)
with L'=0 and S^(+) with L'=2, which, respectively, couple to \psi^1\psi^{2,3}
for the electron mass and masses of atmospheric neutrinos and to
\psi^{2,3}\psi^{2,3} for the \mu- and \tau-masses and one-loop radiative
neutrino masses relevant to solar neutrinos. This mechanism is realized by
utilizing an additional residual discrete symmetry supplied by explicitly
broken L', which guarantees the absence of tree-level neutrino mass terms of
the \psi^{2,3}\psi^{2,3}-type. Pure rotation effects due to the diagonalization
of neutrino and charged-lepton mass matrices are estimated to yield \Delta
m^2_\odot/\Delta m^2_{atm} \leq (m_e/m_\mu)^{3/2}=O(10^{-4}) but the radiative
effects supersede the rotation effects to yield \Delta m^2_\odot/\Delta
m^2_{atm}=O(10^{-2}) as the LMA solution.Comment: 16 pages, RevTeX, including 2 figures with typos and misprints
corrected and with modifications in sections II-B and V, accepted by Nuclear
Physics
Dependence of Spiral Galaxy Distribution on Viewing Angle in RC3
The normalized inclination distributions are presented for the spiral
galaxies in RC3. The results show that, except for the bin of
-, in which the apparent minor isophotal diameters that
are used to obtain the inclinations, are affected by the central bulges, the
distributions for Sa, Sab, Scd and Sd are well consistent with the Monte-Carlo
simulation of random inclinations within 3-, and Sb and Sbc almost, but
Sc is different. One reason for the difference between the real distribution
and the Monte-Carlo simulation of Sc may be that some quite inclined spirals,
the arms of which are inherently loosely wound on the galactic plane and should
be classified to Sc galaxies, have been incorrectly classified to the earlier
ones, because the tightness of spiral arms which is one of the criteria of the
Hubble classification in RC3 is different between on the galactic plane and on
the tangent plane of the celestial sphere. Our result also implies that there
might exist biases in the luminosity functions of individual Hubble types if
spiral galaxies are only classified visually.Comment: 5 pages + 8 figures, LaTe
The 3-3-1 model with S_4 flavor symmetry
We construct a 3-3-1 model based on family symmetry S_4 responsible for the
neutrino and quark masses. The tribimaximal neutrino mixing and the diagonal
quark mixing have been obtained. The new lepton charge \mathcal{L} related to
the ordinary lepton charge L and a SU(3) charge by L=2/\sqrt{3} T_8+\mathcal{L}
and the lepton parity P_l=(-)^L known as a residual symmetry of L have been
introduced which provide insights in this kind of model. The expected vacuum
alignments resulting in potential minimization can origin from appropriate
violation terms of S_4 and \mathcal{L}. The smallness of seesaw contributions
can be explained from the existence of such terms too. If P_l is not broken by
the vacuum values of the scalar fields, there is no mixing between the exotic
and the ordinary quarks at the tree level.Comment: 20 pages, revised versio
Chemical Approaches to Synthetic Drug Delivery Systems for Systemic Applications
Poor water solubility and low bioavailability of active pharmaceutical ingredients (APIs) are major causes of friction in the pharmaceutical industry and represent a formidable hurdle for pharmaceutical drug development. Drug delivery remains the major challenge for the application of new small-molecule drugs as well as biopharmaceuticals. The three challenges for synthetic delivery systems are: (i)â
controlling drug distribution and clearance in the blood; (ii)â
solubilizing poorly water-soluble agents, and (iii)â
selectively targeting specific tissues. Although several polymer-based systems have addressed the first two demands and have been translated into clinical practice, no targeted synthetic drug delivery system has reached the market. This Review is designed to provide a background on the challenges and requirements for the design and translation of new polymer-based delivery systems. This report will focus on chemical approaches to drug delivery for systemic applications
Measuring the cosmological bulk flow using the peculiar velocities of supernovae
We study large-scale coherent motion in our universe using the existing Type
IA supernovae data. If the recently observed bulk flow is real, then some
imprint must be left on supernovae motion. We run a series of Monte Carlo
Markov Chain runs in various redshift bins and find a sharp contrast between
the z 0.05 data. The$z < 0.05 data are consistent with the bulk
flow in the direction (l,b)=({290^{+39}_{-31}}^{\circ},
{20^{+32}_{-32}}^{\circ}) with a magnitude of v_bulk = 188^{+119}_{-103} km/s
at 68% confidence. The significance of detection (compared to the null
hypothesis) is 95%. In contrast, z > 0.05 data (which contains 425 of the 557
supernovae in the Union2 data set) show no evidence for bulk flow. While the
direction of the bulk flow agrees very well with previous studies, the
magnitude is significantly smaller. For example, the Kashlinsky, et al.'s
original bulk flow result of v_bulk > 600 km/s is inconsistent with our
analysis at greater than 99.7% confidence level. Furthermore, our best-fit bulk
flow velocity is consistent with the expectation for the \Lambda CDM model,
which lies inside the 68% confidence limit.Comment: Version published in JCA
Neutrino masses through see-saw mechanism in 3-3-1 models
Some years ago it was shown by Ma that in the context of the electroweak
standard model there are, at the tree level, only three ways to generate small
neutrino masses by the see-saw mechanism via one effective dimension-five
operator. Here we extend this approach to 3-3-1 chiral models showing that in
this case there are several dimension-five operators and we also consider their
tree level realization.Comment: RevTex, 7 pages and 4 .eps figures. Version published in Phys. Rev.
D. with a change in the titl
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