1,380 research outputs found
Interpolating sequences for H∞(BH)
No full textWe prove that under the extended Carleson’s condition, a sequence (xn) ⊂ BH is linear interpolating for H∞(BH) for an infinite dimensional Hilbert space H. In particular, we construct the interpolating functions for each sequence and find a bound for the constant of interpolation.The author is supported by Project MTM 2011-22457 (Ministerio de Economía y Competitividad, Spain) and Project P1-1B2014-35 (Universitat Jaume I, Spain
Thermodynamic products for Sen black hole
No full textWe investigate the properties of inner and outer horizon thermodynamics of Sen black hole (BH) both in Einstein frame (EF) and string frame (SF). We also compute area (or entropy) product, area (or entropy) sum of the said BH in EF as well as SF. In the EF, we observe that the area (or entropy) product is universal, whereas area (or entropy) sum is not universal. On the other hand, in the SF, area (or entropy) product and area (or entropy) sum don’t have any universal behaviour because they all are depends on Arnowitt–Deser–Misner (ADM) mass parameter. We also verify that the first law is satisfied at the Cauchy horizon as well as event horizon (EH). In addition, we also compute other thermodynamic products and sums in the EF as well as in the SF. We further compute the Smarr mass formula and Christodoulou’s irreducible mass formula for Sen BH. Moreover, we compute the area bound and entropy bound for both the horizons. The upper area bound for EH is actually the Penrose like inequality, which is the first geometric inequality in BHs. Furthermore, we compute the central charges of the left and right moving sectors of the dual CFT in Sen/CFT correspondence using thermodynamic relations. These thermodynamic relations on the multi-horizons give us further understanding the microscopic nature of BH entropy (both interior and exterior)
Evaluation and ranking of researchers--Bh Index.
No full textEvaluation and ranking of every author is very crucial as it is widely used to evaluate the performance of the researcher. This article proposes a new method, called Bh-Index, to evaluate the researchers based on the publications and citations. The method is built on h-Index and only the h-core articles are taken into consideration. The method assigns value additions to those articles that receive significantly high citations in comparison to the h-Index of the researcher. It provides a wide range of values for a given h-Index and effective evaluation even for a short period. Use of Bh-Index along with the h-Index gives a powerful tool to evaluate the researchers
X-ray emission from BH+O star binaries expected to descend from the observed galactic WR+O binaries
No full textInternational audienceContext. In the Milky Way, ∼18 Wolf-Rayet+O star (WR+O) binaries are known with estimates of their stellar and orbital parameters. Whereas black hole+O star (BH+O) binaries are thought to evolve from WR+O binaries, only one such system is known in the Milky Way. To resolve this disparity, it was suggested recently that upon core collapse, the WR stars receive large kicks such that most of the binaries are disrupted.Aims. We reassess this issue, with a particular emphasis on the uncertainty in predicting the X-ray emission from wind-accreting BHs in BH+O binaries, which is key to identifying such systems.Methods. BH+O systems are thought to be X-ray bright only when an accretion disk forms around the BHs. We followed the methodology of previous work and applied an improved analytic criterion for the formation of an accretion disk around wind accreting BHs. We then used stellar evolutionary models to predict the properties of the BH+O binaries which are expected to descend from the observed WR+O binaries if the WR stars would form BHs without a natal kick.Results. We find that disk formation sensitively depends on the O stars’ wind velocity, the amount of specific angular momentum carried by the wind, the efficiency of angular momentum accretion by the BH, and the spin of the BH. We show that whereas the assumption of a low wind velocity may lead to the prediction that most of the BH+O star binaries will have an extended X-ray bright period, this is not the case when typical wind velocities of O stars are considered. We find that a high spin of the BH can boost the duration of the X-ray active phase as well as the X-ray brightness during this phase. This produces a strong bias for detecting high mass BH binaries in X-rays with high BH spin parameters.Conclusions. We find that large BH formation kicks are not required to understand the sparsity of X-ray bright BH+O stars in the Milky Way. Probing for a population of X-ray silent BH+O systems with alternative methods can likely inform us about BH kicks and the necessary conditions for high energy emission from high mass BH binaries.Key words: stars: massive / stars: evolution / stars: black holes / X-rays: binaries / binaries: close⋆ The first two authors have contributed equally to this work
ROVIBRATIONAL CHARACTERIZATION OF X BH BY THE EXTRAPOLATION OF PHOTOSELECTED HIGH-RYDBERG SERIES IN BH
No full textAuthor Institution: Department of Chemistry, Purdue University, West Lafayette, IN 47907; Department of Chemistry, University of British Columbia, 6174 University Boulevard,; Vancouver, BC, Canada V6T 1Z3Optical-optical-optical triple resonance spectroscopy of BH isolates high-Rydberg states that form series converging to rotational state specific ionization potentials in the vibrational levels of BH from through . Limits defined by a comprehensive fit of these series to state-detailed thresholds yield rovibrational constants describing the X state of BH. The data provide a first determination of the vibration-rotation interaction parameter cm and a more accurate estimate of cm together with the higher-order anharmonic terms cm and cm. The deperturbation and global fit of series to state-detailed limits also yields a precise value of the adiabatic ionization potential of BH of cm, or eV. High precision is afforded here by the use of graphical analysis techniques, narrow bandwidth laser systems, and an analysis of newly observed, high-principal quantum number Rydberg states that conform well with a Hund's case (d) electron-core coupling limit
More on finite groups with few defining relations
No full textMennicke J, Neumann BH. More on finite groups with few defining relations. Journal of the Australian Mathematical Society. 1989;46(1):132-136.Certain central products of the binary polyhedral groups with finite cyclic groups are here shown to have presentations with two generators and two defining relations; this disproves a conjecture of the second author, stated in J. Austral. Math. Soc. Ser. A 38 (1985), 230–240
COLLISION-INDUCED ELECTRONIC QUENCHING OF
No full textAuthor Institution: Applied Research Corporation; Chemistry Division, Code 6111, Naval Research LaboratoryElectronic quenching cross sections of BH were measured by examining fluorescence decay times in the presence of sixteen collision partners at 298K. The partners exhibit wide variations in mass, electric dipole moment and higher order moments. Except for the extremely low cross sections measured for He and , values range from 5 to . Of the fourteen remaining partners, eleven are represented moderately well by a multipole attractive force model, two (OCS and ) fall well below the expected cross section and one () has an experimental cross section larger than predicted by this model. A temperature comparison is made for the quenching of by CO at 298K and 473K. The measured rate constant at 473K exhibits a 10\% decrease compared to the 298K value with an uncertainty of 11\%
Energy Formula, Surface geometry and Energy Extraction for Kerr-Sen Black Hole
No full textWe evaluate the \emph{surface energy~(), rotational
energy~() and electromagnetic energy~()} for a \emph{Kerr-Sen black hole~(BH)} having the event
horizon~() and the Cauchy horizon~().
Interestingly, we find that the \emph{sum of these three energies is equal to
the mass parameter i.e. }. Moreover in terms of the \emph{ scale parameter
~, the distortion parameter~() and a new
parameter~} which corresponds to the area~(),
the angular momentum ~ and the charge parameter~(), we find that the
\emph{mass parameter in a compact form} %\begin{eqnarray} %{\cal
E}_{s}^{\pm}+{\cal E}_{r}^{\pm}+{\cal E}_{em}^{\pm}={\cal M} =\frac{\zeta_{\pm}
}{2} %\sqrt{\frac{1+2\,\sigma_{\pm}^2}{1-\xi_{\pm}^2}} \nonumber
%\end{eqnarray} which is valid {through all the horizons} ().
We also compute the \emph{equatorial circumference and polar circumference}
which is a gross measure of the BH surface deformation. It is shown that when
the spinning rate of the BH increases, the \emph{equatorial circumference
increases} while the \emph{polar circumference decreases}. Furthermore, we
compute the exact expression of \emph{rotational energy that should be
extracted from the BH via the Penrose process}. The maximum value of rotational
energy which is extractable should occur for \emph{extremal Kerr-Sen BH} i.e.
.Comment: Published in GR
THE REMPI STUDY OF BH IN THE RANGE OF 368-370NM
No full textAuthor Institution: Dept. of Chemistry, Purdue University; Open Laboratory of Bond-Selective Chemistry, University of Science and Technology of ChinaThe mass-selected resonance-enhanced multi-photon ionization (REMPI) of BH in the spectral range of 368-372 nm has been studied. It is shown that the spectral peaks with ion mass 12, 11 and 10 can be assigned to the one-photon transition of 11BH and 10BH free radicals. With very few REMPI studies on BH, the 2-0 band transitions of A-X for 11BH and 10BH are first observed. By using a 40 K rotational temperature and approximately a 600 K background rotational temperature for BH free radicals, the spectra observed was simulated quite well. The observed isotopic shifts of band between 11BH and 10BH, which is between 11.7 and 13.0 cm-1, are mainly due to the vibrational isotope shifts
Device-Aware Test for Back-Hopping Defects in STT-MRAMs
No full textThe development of Spin-transfer torque magnetic RAM (STT-MRAM) mass production requires high-quality dedicated test solutions, for which understanding and modeling of manufacturing defects of the magnetic tunnel junction (MTJ) is crucial. This paper introduces and characterizes a new defect called Back-Hopping (BH); it also provides its fault models and test solutions. The BH defect causes MTJ state to oscillate during write operations, leading to write failures. The characterization of the defect is carried out based on manufactured MTJ devices. Due to the observed non-linear characteristics, the BH defect cannot be modelled with a linear resistance. Hence, device-aware defect modeling is applied by considering the intrinsic physical mechanisms; the model is then calibrated based on measurement data. Thereafter, the fault modeling and analysis is performed based on circuit-level simulations; new fault primitives/models are derived. These accurately describe the way the STT-MRAM behaves in the presence of BH defect. Finally, dedicated march test and a Design-for-Test solutions are proposed.Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.Computer EngineeringQuantum & Computer Engineerin
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