76 research outputs found

    Bounded H\mathbf{H_\infty}-Calculus for Differential Operators on Conic Manifolds with Boundary

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    We derive conditions that ensure the existence of a bounded HH_\infty-calculus in weighted LpL_p-Sobolev spaces for closed extensions AT\underline{A}_T of a differential operator AA on a conic manifold with boundary, subject to differential boundary conditions TT. In general, these conditions ask for a particular pseudodifferential structure of the resolvent (λAT)1(\lambda-\underline{A}_T)^{-1} in a sector ΛC\Lambda\subset\mathbf{C}. In case of the minimal extension they reduce to parameter-ellipticity of the boundary value problem (A,T)(A,T). Examples concern the Dirichlet and Neumann Laplacians.Comment: 23 page

    Maximal L p -regularity for the Laplacian on Lipschitz domains

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    We consider the Laplacian with Dirichlet or Neumann boundary conditions on bounded Lipschitz domains ?, both with the following two domains of definition:D1(?) = {u ? W1,p(?) : ?u ? Lp(?), Bu = 0}, orD2(?) = {u ? W2,p(?) : Bu = 0}, where B is the boundary operator.We prove that, under certain restrictions on the range of p, these operators generate positive analytic contraction semigroups on Lp(?) which implies maximal regularity for the corresponding Cauchy problems. In particular, if ? is bounded and convex and 1 < p ? 2, the Laplacian with domain D2(?) has the maximal regularity property, as in the case of smooth domains. In the last part,we construct an example that proves that, in general, the Dirichlet–Laplacian with domain D1(?) is not even a closed operator

    The WEBT Campaign on the Blazar 3C279 in 2006

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    The quasar 3C279 was the target of an extensive multiwavelength monitoring campaign from January through April 2006, including an optical-IR-radio monitoring campaign by the Whole Earth Blazar Telescope (WEBT) collaboration. In this paper we focus on the results of the WEBT campaign. The source exhibited substantial variability of optical flux and spectral shape, with a characteristic time scale of a few days. The variability patterns throughout the optical BVRI bands were very closely correlated with each other. In intriguing contrast to other (in particular, BL Lac type) blazars, we find a lag of shorter- behind longer-wavelength variability throughout the RVB ranges, with a time delay increasing with increasing frequency. Spectral hardening during flares appears delayed with respect to a rising optical flux. This, in combination with the very steep IR-optical continuum spectral index of ~ 1.5 - 2.0, may indicate a highly oblique magnetic field configuration near the base of the jet. An alternative explanation through a slow (time scale of several days) acceleration mechanism would require an unusually low magnetic field of < 0.2 G, about an order of magnitude lower than inferred from previous analyses of simultaneous SEDs of 3C279 and other FSRQs with similar properties.Comment: Accepted for publication in Ap

    Preparation of polyclonal and monoclonal anti-idiotypic antibodies against morphine-specific immunoglobulins

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    The preparation and study of anti-idiotypic (secondary) antibodies (Ab2) against monoclonal primary antibodies (Ab1) specific to biologically active molecules with a known structure is of great scientific and practical importance. Due to partial antigenic similarity of Ab2 and the initial antigen structures, these antibodies can be the basis of the vaccine, if the antigen usage is not possible, or is limited by law. In particular, one may create Ab2-based preparations, designed for immunization, in order to prevent and treat the drug addiction. The value of Ab2 properties increases even more if Ab1, used to obtain them, recognize different parts of the antigen molecule, which makes it possible to obtain second-generation antibodies with a wide range of specificity. In this work, the morphine-like polyclonal and monoclonal Ab2 were obtained. In each case, as the first-generation immunoglobulins for immunization, we used two murine monoclonal antibodies (mAbs) specific to different morphine derivatives: 3K11 antibodies to 3-0-carboxymethyl (CMM) and 2-p-carboxyphenylazomethyl (FAM) derivatives, as well as 6G1 antibodies to 6-hemisuccinyl derivative (GSM). After immunization of the horse with Ab1 and development of immune response, three pools of specific polyclonal antibodies were isolated from the animal blood serum: horse anti-species antibodies to the total mouse immunoglobulins (HAM); horse anti-idiotypic antibodies against 3K11 antibodies (HAM-K11), and against 6G1 antibodies (HAM-G1). In parallel, immunization of mice with 3K11 and 6G1 antibodies and fusion of obtained lymphocytes with Sp2/0 mouse myeloma cells by the Milstein-Köhler method resulted in three producers of anti-idiotypic antibodies: a clone producing mouse monoclonal Ab2 specific for mAb-6G1 (AIG1), as well as clones producing anti-mAb-3K11 antibodies (AI-K11A and AI-K11B). The physico-chemical and antigenic properties of all the Ab2 obtained were characterized. It was shown that the horse anti-idiotypic immunoglobulins not only belong to different classes, but are also polyvalent, while all monoclonal Ab2 obtained are represented by IgM immunoglobulins, being also strictly specific to the corresponding first-generation antibodies. Subsequently, the morphine-like properties of the first domestic polyclonal and monoclonal Ab2 obtained in the work will be investigated in a cellular model. Likewise, we shall study their ability to induce Ab3 as well as morphine-specific Ab1

    The WEBT BL Lacertae Campaign 2001 and its extension : Optical light curves and colour analysis 1994–2002

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    BL Lacertae has been the target of four observing campaigns by the Whole Earth Blazar Telescope (WEBT) collaboration. In this paper we present UBVRI light curves obtained by theWEBT from 1994 to 2002, including the last, extended BL Lac 2001 campaign. A total of about 7500 optical observations performed by 31 telescopes from Japan to Mexico have been collected, to be added to the ∼15 600 observations of the BL Lac Campaign 2000. All these data allow one to follow the source optical emission behaviour with unprecedented detail. The analysis of the colour indices reveals that the flux variability can be interpreted in terms of two components: longer-term variations occurring on a fewday time scale appear as mildly-chromatic events, while a strong bluer-when-brighter chromatism characterizes very fast (intraday) flares. By decoupling the two components, we quantify the degree of chromatism inferring that longer-term flux changes imply moving along a ∼0.1 bluerwhen- brighter slope in the B − R versus R plane; a steeper slope of ∼0.4 would distinguish the shorter-term variations. This means that, when considering the long-term trend, the B-band flux level is related to the R-band one according to a power law of index ∼1.1. Doppler factor variations on a “convex” spectrum could be the mechanism accounting for both the long-term variations and their slight chromatism.Reig Torres, Pablo, [email protected]

    The GRANDMA network in preparation for the fourth gravitational-wave observing run

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    GRANDMA is a world-wide collaboration with the primary scientific goal ofstudying gravitational-wave sources, discovering their electromagneticcounterparts and characterizing their emission. GRANDMA involves astronomers,astrophysicists, gravitational-wave physicists, and theorists. GRANDMA is now atruly global network of telescopes, with (so far) 30 telescopes in bothhemispheres. It incorporates a citizen science programme (Kilonova-Catcher)which constitutes an opportunity to spread the interest in time-domainastronomy. The telescope network is an heterogeneous set of already-existingobserving facilities that operate coordinated as a single observatory. Withinthe network there are wide-field imagers that can observe large areas of thesky to search for optical counterparts, narrow-field instruments that dotargeted searches within a predefined list of host-galaxy candidates, andlarger telescopes that are devoted to characterization and follow-up of theidentified counterparts. Here we present an overview of GRANDMA after the thirdobserving run of the LIGO/VIRGO gravitational-wave observatories in 201920202019-2020and its ongoing preparation for the forthcoming fourth observational campaign(O4). Additionally, we review the potential of GRANDMA for the discovery andfollow-up of other types of astronomical transients.<br

    Multifrequency variability of the blazar AO 0235+164. The WEBT campaign in 2004-2005 and long-term SED analysis

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    A huge multiwavelength campaign targeting the blazar AO 0235+164 was organized by the Whole Earth Blazar Telescope (WEBT) in 2003-2005 to study the variability properties of the source. Monitoring observations were carried out at cm and mm wavelengths, and in the near-IR and optical bands, while three pointings by the XMM-Newton satellite provided information on the X-ray and UV emission. We present the data acquired during the second observing season, 2004-2005, by 27 radio-to-optical telescopes. They reveal an increased near-IR and optical activity with respect to the previous season. Increased variability is also found at the higher radio frequencies, down to 15 GHz, but not at the lower ones. The radio (and optical) outburst predicted to peak around February-March 2004 on the basis of the previously observed 5-6 yr quasi-periodicity did not occur. The analysis of the optical light curves reveals now a longer characteristic time scale of 8 yr, which is also present in the radio data. The spectral energy distributions corresponding to the XMM-Newton observations performed during the WEBT campaign are compared with those pertaining to previous pointings of X-ray satellites. Bright, soft X-ray spectra can be described in terms of an extra component, which appears also when the source is faint through a hard UV spectrum and a curvature of the X-ray spectrum. Finally, there might be a correlation between the X-ray and optical bright states with a long time delay of about 5 yr, which would require a geometrical interpretation.Comment: 14 pages, 10 figures (8 included in the text and 2 PNG files), in press for A&
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