38 research outputs found

    Free Boson Representation of qq-Vertex Operators and their Correlation Functions

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    A bosonization scheme of the qq-vertex operators of \uqa for arbitrary level is obtained. They act as intertwiners among the highest weight modules constructed in a bosonic Fock space. An integral formula is proposed for NN-point functions and explicit calculation for two-point function is presented.Comment: 22 pages, latex file, UT-618 (revised version

    Excited States of Calogero-Sutherland Model and Singular Vectors of the WNW_N Algebra

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    Using the collective field method, we find a relation between the Jack symmetric polynomials, which describe the excited states of the Calogero-Sutherland model, and the singular vectors of the WNW_N algebra. Based on this relation, we obtain their integral representations. We also give a direct algebraic method which leads to the same result, and integral representations of the skew-Jack polynomials.Comment: LaTeX, 29 pages, 2 figures, New sections for skew-Jack polynomial and example of singular vectors adde

    Free Boson Realization of Uq(slN^)U_q(\widehat{sl_N})

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    We construct a realization of the quantum affine algebra Uq(slN^)U_q(\widehat{sl_N}) of an arbitrary level kk in terms of free boson fields. In the q ⁣ ⁣1q\!\rightarrow\! 1 limit this realization becomes the Wakimoto realization of slN^\widehat{sl_N}. The screening currents and the vertex operators(primary fields) are also constructed; the former commutes with Uq(slN^)U_q(\widehat{sl_N}) modulo total difference, and the latter creates the Uq(slN^)U_q(\widehat{sl_N}) highest weight state from the vacuum state of the boson Fock space.Comment: 24 pages, LaTeX, RIMS-924, YITP/K-101

    Search for eccentric black hole coalescences during the third observing run of LIGO and Virgo

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    Despite the growing number of confident binary black hole coalescences observed through gravitational waves so far, the astrophysical origin of these binaries remains uncertain. Orbital eccentricity is one of the clearest tracers of binary formation channels. Identifying binary eccentricity, however, remains challenging due to the limited availability of gravitational waveforms that include effects of eccentricity. Here, we present observational results for a waveform-independent search sensitive to eccentric black hole coalescences, covering the third observing run (O3) of the LIGO and Virgo detectors. We identified no new high-significance candidates beyond those that were already identified with searches focusing on quasi-circular binaries. We determine the sensitivity of our search to high-mass (total mass M>70 M⊙) binaries covering eccentricities up to 0.3 at 15 Hz orbital frequency, and use this to compare model predictions to search results. Assuming all detections are indeed quasi-circular, for our fiducial population model, we place an upper limit for the merger rate density of high-mass binaries with eccentricities 0<e≤0.3 at 0.33 Gpc−3 yr−1 at 90\% confidence level

    Ultralight vector dark matter search using data from the KAGRA O3GK run

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    Among the various candidates for dark matter (DM), ultralight vector DM can be probed by laser interferometric gravitational wave detectors through the measurement of oscillating length changes in the arm cavities. In this context, KAGRA has a unique feature due to differing compositions of its mirrors, enhancing the signal of vector DM in the length change in the auxiliary channels. Here we present the result of a search for U(1)B−L gauge boson DM using the KAGRA data from auxiliary length channels during the first joint observation run together with GEO600. By applying our search pipeline, which takes into account the stochastic nature of ultralight DM, upper bounds on the coupling strength between the U(1)B−L gauge boson and ordinary matter are obtained for a range of DM masses. While our constraints are less stringent than those derived from previous experiments, this study demonstrates the applicability of our method to the lower-mass vector DM search, which is made difficult in this measurement by the short observation time compared to the auto-correlation time scale of DM

    Observation of gravitational waves from the coalescence of a 2.5−4.5 M⊙ compact object and a neutron star

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    Search for gravitational-lensing signatures in the full third observing run of the LIGO-Virgo network

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    Gravitational lensing by massive objects along the line of sight to the source causes distortions of gravitational wave-signals; such distortions may reveal information about fundamental physics, cosmology and astrophysics. In this work, we have extended the search for lensing signatures to all binary black hole events from the third observing run of the LIGO--Virgo network. We search for repeated signals from strong lensing by 1) performing targeted searches for subthreshold signals, 2) calculating the degree of overlap amongst the intrinsic parameters and sky location of pairs of signals, 3) comparing the similarities of the spectrograms amongst pairs of signals, and 4) performing dual-signal Bayesian analysis that takes into account selection effects and astrophysical knowledge. We also search for distortions to the gravitational waveform caused by 1) frequency-independent phase shifts in strongly lensed images, and 2) frequency-dependent modulation of the amplitude and phase due to point masses. None of these searches yields significant evidence for lensing. Finally, we use the non-detection of gravitational-wave lensing to constrain the lensing rate based on the latest merger-rate estimates and the fraction of dark matter composed of compact objects

    Crystal Structure of Asparagine Synthetase Reveals a Close Evolutionary Relationship to Class II Aminoacyl-tRNA Synthetase (MOLECULAR BIOFUNCTION-Functional Molecular Conversion)

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    The crystal structure of E. coli asparagine synthetase has been determined by X-ray diffraction analysis at 2.5 A resolution. The overall structure of the enzyme is remarkably similar to that of the catalytic domain of yeast aspartyl-tRNA synthetase despite low sequence similarity. These enzymes have a common reaction mechanism that implies the formation of aminoacyl-adenylate intermediate. The active site architecture and most of the catalytic residues are also conserved in both enzymes. These enzymes have probably evolved from a common ancestor even though their sequence similarities are small

    Mechanism-Based Inactivation of E.coli g-Glutamylcysteine Synthetase by Phosphinic Acid- and Sulfoximine-Based Transition-State Analogues (MOLECULAR BIOFUNCTION-Functional Molecular Conversion)

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    On the basis of the proposed reaction mechanisms of g-glutamylcysteine synthetase, tetrahedral phosphinic acid- and sulfoximine-based compounds 1 and 2 were synthesized and evaluated as inhibitors of E. coli g- glutamylcysteine synthetase. Both compounds inactivated the enzyme in a time-dependent manner with an overall inhibition constant Ki of 4.95 and 0.39 mM, respectively. The enzyme inactivation was observed only when ATP was present, suggesting that the inhibitors are phosphorylated in the enzyme active site, serving as a mechanism-based inactivator. The inhibition potency was 10 and 100 times, respectively, higher than L-buthionine-SR-sulfoximine, a well known inhibitor of this enzyme. In particular, the sulfoximine 2 served as an almost irreversible enzyme inactivator with a very slow regain of enzyme activity (t 1/2 = 3.9 day). This compound may find a potential use as chemotherapeutic agent
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