Focusing of positron bunch when moving in electron bunch wakefield in the dielectric waveguide filled with plasma

The results of numerical PIC-simulation of focusing accelerated (test) positron and drive electron bunches in the dielectric waveguide filled with radially heterogeneous plasma with the vacuum channel are given in the paper. The wakefield was excited by electron bunch in quartz dielectric tube, inserted into cylindrical metal waveguide. The internal area of dielectric tube has been filled with plasma different transverse density profiles, heterogeneous on radius, with the vacuum channel along waveguide axis. Plasma density for all studied cases was so low that plasma frequency was less, than the frequency of the main dielectric mode. Results of numerical PIC simulation have shown that possibility of simultaneous acceleration and focusing of the test positron bunch are possible in the wakefield. The best acceleration happens in case of plasma absence, however at that there is no focusing of test positron bunch.Наведено результати чисельного PIC-моделювання фокусування тестового позитронного й драйверного електронного згустків у діелектричному хвилеводі, заповненому радіально-неоднорідною плазмою з вакуумним каналом. Кільватерне поле збуджувалося електронним згустком у кварцовій діелектричній трубці, що вставлена в циліндричний металевий хвилевід. Внутрішня область діелектричної трубки була заповнена плазмою з різними поперечними профілями щільності неоднорідними по радіусу з вакуумним каналом уздовж осі хвилеводу. Плазмова щільність для всіх досліджених випадків була настільки низькою, що плазмова частота була меншa, ніж частота основної діелектричної моди. Результати чисельного PIC-моделювання показали можливість одночасного прискорення й фокусування тестового позитронного згусткa в кільватерному полі. Найкраще прискорення відбувається у випадку відсутності плазми, однак при цьому відсутнє й фокусування тестового згусткa позитронів.Приведены результаты численного PIC-моделирования фокусировки тестового позитронного и драйверного электронного сгустков в диэлектрическом волноводе, заполненном радиально-неоднородной плазмой с вакуумным каналом. Кильватерное поле возбуждалось электронным сгустком в кварцевой диэлектрической трубке, вставленной в цилиндрический металлический волновод. Внутренняя область диэлектрической трубки была заполнена плазмой с различными поперечными профилями плотности, неоднородными по радиусу с вакуумным каналом вдоль оси волновода. Плазменная плотность для всех исследованных случаев была настолько низкой, что плазменная частота была меньше, чем частота основной диэлектрической моды. Результаты численного PIC-моделирования показали возможность одновременного ускорения и фокусировки тестового позитронного сгустка в кильватерном поле. Наилучшее ускорение происходит в случае отсутствия плазмы, однако при этом отсутствует фокусировка тестового сгустка позитронов

A joint Fermi-GBM and Swift-BAT analysis of gravitational-wave candidates from the third gravitational-wave observing run

We present Fermi Gamma-ray Burst Monitor (Fermi-GBM) and Swift Burst Alert Telescope (Swift-BAT) searches for gamma-ray/X-ray counterparts to gravitational-wave (GW) candidate events identified during the third observing run of the Advanced LIGO and Advanced Virgo detectors. Using Fermi-GBM onboard triggers and subthreshold gamma-ray burst (GRB) candidates found in the Fermi-GBM ground analyses, the Targeted Search and the Untargeted Search, we investigate whether there are any coincident GRBs associated with the GWs. We also search the Swift-BAT rate data around the GW times to determine whether a GRB counterpart is present. No counterparts are found. Using both the Fermi-GBM Targeted Search and the Swift-BAT search, we calculate flux upper limits and present joint upper limits on the gamma-ray luminosity of each GW. Given these limits, we constrain theoretical models for the emission of gamma rays from binary black hole mergers

Constraints on the cosmic expansion history from GWTC–3

We use 47 gravitational wave sources from the Third LIGO–Virgo–Kamioka Gravitational Wave Detector Gravitational Wave Transient Catalog (GWTC–3) to estimate the Hubble parameter H(z), including its current value, the Hubble constant H0. Each gravitational wave (GW) signal provides the luminosity distance to the source, and we estimate the corresponding redshift using two methods: the redshifted masses and a galaxy catalog. Using the binary black hole (BBH) redshifted masses, we simultaneously infer the source mass distribution and H(z). The source mass distribution displays a peak around 34 M⊙, followed by a drop-off. Assuming this mass scale does not evolve with the redshift results in a H(z) measurement, yielding ${H}_{0}={68}_{-8}^{+12}\,\mathrm{km}\ \,\ {{\rm{s}}}^{-1}\,{\mathrm{Mpc}}^{-1}$ (68% credible interval) when combined with the H0 measurement from GW170817 and its electromagnetic counterpart. This represents an improvement of 17% with respect to the H0 estimate from GWTC–1. The second method associates each GW event with its probable host galaxy in the catalog GLADE+, statistically marginalizing over the redshifts of each event's potential hosts. Assuming a fixed BBH population, we estimate a value of ${H}_{0}={68}_{-6}^{+8}\,\mathrm{km}\ \,\ {{\rm{s}}}^{-1}\,{\mathrm{Mpc}}^{-1}$ with the galaxy catalog method, an improvement of 42% with respect to our GWTC–1 result and 20% with respect to recent H0 studies using GWTC–2 events. However, we show that this result is strongly impacted by assumptions about the BBH source mass distribution; the only event which is not strongly impacted by such assumptions (and is thus informative about H0) is the well-localized event GW190814

Search for gravitational-wave transients associated with magnetar bursts in advanced LIGO and advanced Virgo data from the third observing run

Gravitational waves are expected to be produced from neutron star oscillations associated with magnetar giant f lares and short bursts. We present the results of a search for short-duration (milliseconds to seconds) and longduration (∼100 s) transient gravitational waves from 13 magnetar short bursts observed during Advanced LIGO, Advanced Virgo, and KAGRA’s third observation run. These 13 bursts come from two magnetars, SGR1935 +2154 and SwiftJ1818.0−1607. We also include three other electromagnetic burst events detected by FermiGBM which were identified as likely coming from one or more magnetars, but they have no association with a known magnetar. No magnetar giant flares were detected during the analysis period. We find no evidence of gravitational waves associated with any of these 16 bursts. We place upper limits on the rms of the integrated incident gravitational-wave strain that reach 3.6 × 10−²³ Hz at 100 Hz for the short-duration search and 1.1 ×10−²² Hz at 450 Hz for the long-duration search. For a ringdown signal at 1590 Hz targeted by the short-duration search the limit is set to 2.3 × 10−²² Hz. Using the estimated distance to each magnetar, we derive upper limits upper limits on the emitted gravitational-wave energy of 1.5 × 1044 erg (1.0 × 1044 erg) for SGR 1935+2154 and 9.4 × 10^43 erg (1.3 × 1044 erg) for Swift J1818.0−1607, for the short-duration (long-duration) search. Assuming isotropic emission of electromagnetic radiation of the burst fluences, we constrain the ratio of gravitational-wave energy to electromagnetic energy for bursts from SGR 1935+2154 with the available fluence information. The lowest of these ratios is 4.5 × 103

SNP-detecting DNA technologies: Solving problems of applied biochemistry

The heterozygosity of CANP3, ACTN3, and GHR genes in specialized collections was studied using state-of-the-art DNA technologies for DNA analysis. A new dinucleotide deletion (AC) at the beginning of exon 21 was identified in five individuals with a heterozygous CANP3 gene. Analysis of polymorphism (1747 C → T) of the ACTN3 gene demonstrated a positive association of allele C with high muscular performance. Real-time PCR assay of SNP1630 (A → C) in the GHR gene suggested a putative negative association of allele C of this SNP with high muscular performance. © 2005 MAIK "Nauka/Interperiodica"

SNP-detecting DNA technologies: Solving problems of applied biochemistry

The heterozygosity of CANP3, ACTN3, and GHR genes in specialized collections was studied using state-of-the-art DNA technologies for DNA analysis. A new dinucleotide deletion (AC) at the beginning of exon 21 was identified in five individuals with a heterozygous CANP3 gene. Analysis of polymorphism (1747 C → T) of the ACTN3 gene demonstrated a positive association of allele C with high muscular performance. Real-time PCR assay of SNP1630 (A → C) in the GHR gene suggested a putative negative association of allele C of this SNP with high muscular performance. © 2005 MAIK "Nauka/Interperiodica"