578 research outputs found
Remarks on free mutual information and orbital free entropy
The present notes provide a proof of
for any pair of projections with
. The proof includes new extra observations, such as a
subordination result in terms of Loewner equations. A study of the general case
is also given.Comment: 13 page
Quantum Resonance viewed as Weak Measurement
Quantum resonance, i.e., amplification in transition probability available
under certain conditions, offers a powerful means for determining fundamental
quantities in physics, including the time duration of the second adopted in the
SI units and neutron's electric dipole moment which is directly linked to CP
violation. We revisit two of the typical examples, the Rabi resonance and the
Ramsey resonance, and show that both of these represent the weak value
amplification and that near the resonance points they share exactly the same
behavior of transition probabilities except for the measurement strength whose
difference leads to the known advantage of the Ramsey resonance in the
sensitivity. Conversely, this suggests that the weak value may be measured, for
instance, through the Ramsey resonance. In fact, we argue that previous
measurements of neutron electric dipole moment have potentially determined the
imaginary component of the weak value of the spin of neutrons with higher
precision than the conventional weak value measurement via neutron beams by
three orders of magnitude.Comment: 13 pages, 2 figure
Fine soil particle aggregation in ultra-fine bubble irrigated paddy fields
The flotation method of ultra-fine bubbles (UFB) aims to address pollution and has been used for combating the undesirable reducibility of paddy soils. Hence, water containing UFB is gaining increasing attention for potential agricultural applications. Although certain hypotheses have been proposed, such as the collection of ions in water through the electrical characteristic of UFB, no clear experimental data have been provided. We found that improvement in turbidity may cause the adsorption of fine soil particles in the water by the UFB, thereby improving the quality of the water. The data from the paddy field showed that a decrease in turbidity (below 2 nephelometric turbidity units) occurred over a short period of time (3 days). UFB concentration is directly related to turbidity with a coefficient of determination of 0.93. This phenomenon was also observed through the distribution of bubbles and soil particles, where the average particle size increased because of the aggregation of soil particles and the decrease in turbidity in the paddy field, indicating that UFB collect soil particles and thereby improve water quality. Therefore, UFB are highly effective in cleaning rice field water and will be a preferred method for purifying the environment in the future
A NuSTAR and XMM-Newton Study of the Two Most Actively Star-forming Green Pea Galaxies (SDSS J0749+3337 and SDSS J0822+2241)
We explore X-ray evidence for the presence of active galactic nuclei (AGNs)
in the two most actively star-forming Green Pea galaxies (GPs), SDSS J0749+3337
and SDSS J0822+2241, which have star-formation rates (SFRs) of
yr and yr, respectively. The GPs have red
mid-infrared (MIR) spectral energy distributions and higher 22 m
luminosities than expected from a proxy of the SFR (H luminosity),
consistent with hosting AGNs with 2-10 keV luminosities of erg
s. We thus obtain and analyze the first hard ( 10 keV) X-ray data
observed with NuSTAR and archival XMM-Newton data below 10 keV. From the NuSTAR
20 ksec data, however, we find no significant hard X-ray emission. By
contrast, soft X-ray emission with 0.5--8 keV luminosities of
erg s is significantly detected in both targets, which can be explained
only by star formation (SF). A possible reason for the lack of clear evidence
is that a putative AGN torus absorbs most of the X-ray emission. Applying a
smooth-density AGN torus model, we determine minimum hydrogen column densities
along the equatorial plane () consistent with the
non-detection. The results indicate
cm for SDSS J0749+3337 and
cm for SDSS J0822+2241. Therefore, the GPs may host such heavily
obscured AGNs. Otherwise, no AGN exists and the MIR emission is ascribed to SF.
Active SF in low-mass galaxies is indeed suggested to reproduce red MIR colors.
This would imply that diagnostics based on MIR photometry data alone may
misidentify such galaxies as AGNs.Comment: 12 pages, 3 tables, 5 figures, accepted for publication in Ap
The Sunyaev-Zel'dovich Effect at Five Arc-seconds: RXJ1347.5-1145 Imaged by ALMA
We present the first image of the thermal Sunyaev-Zel'dovich effect (SZE)
obtained by the Atacama Large Millimeter/submillimeter Array (ALMA). Combining
7-m and 12-m arrays in Band 3, we create an SZE map toward a galaxy cluster
RXJ1347.5-1145 with 5 arc-second resolution (corresponding to the physical size
of 20 kpc/h), the highest angular and physical spatial resolutions achieved to
date for imaging the SZE, while retaining extended signals out to 40
arc-seconds. The 1-sigma statistical sensitivity of the image is 0.017 mJy/beam
or 0.12 mK_CMB at the 5 arc-second full width at half maximum. The SZE image
shows a good agreement with an electron pressure map reconstructed
independently from the X-ray data and offers a new probe of the small-scale
structure of the intracluster medium. Our results demonstrate that ALMA is a
powerful instrument for imaging the SZE in compact galaxy clusters with
unprecedented angular resolution and sensitivity. As the first report on the
detection of the SZE by ALMA, we present detailed analysis procedures including
corrections for the missing flux, to provide guiding methods for analyzing and
interpreting future SZE images by ALMA.Comment: 20 pages, 13 figures. Accepted for publication in PAS
Cool core disturbed: Observational evidence for coexistence of sub-sonic sloshing gas and stripped shock-heated gas around the core of RX J1347.5-1145
RXJ1347.5-1145 (z = 0.451) is one of the most luminous X-ray galaxy clusters,
which hosts a prominent cool core and exhibits a signature of a major merger.
We present the first direct observational evidence for sub-sonic nature of
sloshing motion of the cool core. We find that a residual X-ray image from the
Chandra X-ray Observatory after removing the global emission shows a clear
dipolar pattern characteristic of gas sloshing, whereas we find no significant
residual in the Sunyaev-Zel'dovich effect (SZE) image from the Atacama Large
Millimeter/submillimeter Array (ALMA). We estimate the equation of state of
perturbations in the gas from the X-ray and SZE residual images. The inferred
velocity is 420 +310 -420 km s-1, which is much lower than the adiabatic sound
speed of the intracluster medium in the core. We thus conclude that the
perturbation is nearly isobaric, and gas sloshing motion is consistent with
being in pressure equilibrium. Next, we report evidence for gas stripping of an
infalling subcluster, which likely shock-heats gas to high temperature well in
excess of 20 keV. Using mass distribution inferred from strong lensing images
of the Hubble Space Telescope (HST), we find that the mass peak is located away
from the peak position of stripped gas with statistical significance of >
5{\sigma}. Unlike for the gas sloshing, the velocity inferred from the equation
of state of the excess hot gas is comparable to the adiabatic sound speed
expected for the 20 keV intracluster medium. All of the results support that
the southeast substructure is created by a merger. On the other hand, the
positional offset between the mass and the gas limits the self-interaction
cross section of dark matter to be less than 3.7 h-1 cm2 g-1 (95% CL).Comment: 18 pages, 10 figures, accepted for publication in Ap
Functional mutations in spike glycoprotein of Zaire ebolavirus associated with an increase in infection efficiency
Ebola virus (EBOV) is extremely virulent, and its glycoprotein is necessary for viral entry. EBOV may adapt to its new host humans during outbreaks by acquiring mutations especially in glycoprotein, which allows EBOV to spread more efficiently. To identify these evolutionary selected mutations and examine their effects on viral infectivity, we used experimental–phylogenetic–structural interdisciplinary approaches. In evolutionary analysis of all available Zaire ebolavirus glycoprotein sequences, we detected two codon sites under positive selection, which are located near/within the region critical for the host‐viral membrane fusion, namely alanine‐to‐valine and threonine‐to‐isoleucine mutations at 82 (A82V) and 544 (T544I), respectively. The fine‐scale transmission dynamics of EBOV Makona variants that caused the 2014–2015 outbreak showed that A82V mutant was fixed in the population, whereas T544I was not. Furthermore, pseudotype assays for the Makona glycoprotein showed that the A82V mutation caused a small increase in viral infectivity compared with the T544I mutation. These findings suggest that mutation fixation in EBOV glycoprotein may be associated with their increased infectivity levels; the mutant with a moderate increase in infectivity will fix. Our findings showed that a driving force for Ebola virus evolution via glycoprotein may be a balance between costs and benefits of its virulence
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