138 research outputs found

    Pole-skipping points in 2D gravity and SYK model

    Full text link
    We represent the first investigation of pole-skipping on both the gravity and field theory sides. In contrast to the higher dimensional models, there is no momentum degree of freedom in (1+1)−(1+1)-dimensional bulk theory. Thus, we then consider a scalar field mass as our degree of freedom for the pole-skipping phenomenon instead of momentum. The pole-skipping frequencies of the scalar field in 2D gravity are the same as higher dimensional cases: ω=−i2πTn\omega=-i2\pi Tn for positive integer nn. At each of these frequencies, there is a corresponding pole-skipping mass, so the pole-skipping points exist in the (ω,m)(\omega,m) space. We also compute the pole-skipping points of the SYK model in (ω,h)(\omega, h) space where hh is the dimension of the bilinear primary operator. We find that there is a one-to-one correspondence of the pole-skipping points between the JT gravity and the SYK model. To obtain the pole-skipping points, we need to consider the parameter ϵ\epsilon related to chemical potential on the horizon of charged JT gravity and the particle-hole asymmetric parameter E\mathcal{E} of the complex SYK model as shift parameters. This highlights the ϵ−E\epsilon-\mathcal{E} correspondence in relation to pole-skipping

    Spin-dependent structure functions g^1\hat g_1 and g^2\hat g_2 for inclusive spin-half baryon production in electron-positron annihilation

    Full text link
    Two spin-dependent structure functions g^1\hat g_1 and g^2\hat g_2 for the inclusive spin-half baryon production in electron-positron annihilation are studied in the context of QCD factorization as well as in the naive quark parton model. As a result, it is found that the sum of g^1\hat g_1 and g^2\hat g_2 is related to h^1\hat h_1 and g^T\hat g_T, two quark fragmentation functions defined by Jaffe and Ji. In connection with the measurement of quark fragmentation functions, the possible phenomenological consequences are discussed.Comment: RevTex, four Ps figures, to appear in Phys. Rev.

    Long decay length of magnon-polarons in BiFeO3/La0.67Sr0.33MnO3 heterostructures

    Get PDF
    Long-distance magnon transport is highly desired for magnonics. Here, the authors demonstrate a millimetre-long magnon decay length in multiferroic heterostructures, which is attributed to magnon-polarons induced by the magnetoelastic coupling. Magnons can transfer information in metals and insulators without Joule heating, and therefore are promising for low-power computation. The on-chip magnonics however suffers from high losses due to limited magnon decay length. In metallic thin films, it is typically on the tens of micrometre length scale. Here, we demonstrate an ultra-long magnon decay length of up to one millimetre in multiferroic/ferromagnetic BiFeO3(BFO)/La0.67Sr0.33MnO3(LSMO) heterostructures at room temperature. This decay length is attributed to a magnon-phonon hybridization and is more than two orders of magnitude longer than that of bare metallic LSMO. The long-distance modes have high group velocities of 2.5 km s(-1) as detected by time-resolved Brillouin light scattering. Numerical simulations suggest that magnetoelastic coupling via the BFO/LSMO interface hybridizes phonons in BFO with magnons in LSMO to form magnon-polarons. Our results provide a solution to the long-standing issue on magnon decay lengths in metallic magnets and advance the bourgeoning field of hybrid magnonics

    Protective Effect of 18 β

    Get PDF
    Triptolide (TP) is the major active component of Tripterygium wilfordii Hook F (TWHF) and possesses multiple pharmacological effects. However, hepatotoxicity of TP which is one of the toxic properties slows its progression in clinical application. 18β-Glycyrrhetinic acid (GA) is the main bioactive ingredient of Licorice (Glycyrrhiza glabra L.), a herbal medicine famous for its detoxification. This study aims to investigate whether GA possesses protective effect against TP-induced hepatotoxicity in rats. TP interference markedly elevated serum levels of ALT, AST, and ALP, caused evident liver histopathological changes, and elevated hepatic TNF-α, IL-6, IL-1β, and IFN-γ as well as nuclear translocation of NF-κB. TP also significantly elevated liver MDA and declined hepatic activities of SOD, CAT, and GSH-Px. Assay of TUNEL and apoptosis proteins (Bax, Bcl-2, and active caspase-3) showed that TP induced severe hepatocellular apoptosis. In contrast, low-dose GA (50 mg/kg) significantly reversed TP-induced changes above. However, high-dose GA (100 mg/kg) had no such effect. Overall, these findings indicated that low-dose GA but not high-dose GA exhibited a protective effect against TP-induced hepatotoxicity in rats by anti-inflammation, antioxidation, and antiapoptosis, which suggests that the doses of GA/Licorice should be carefully considered when used together with TWHF or TWHF preparations

    Measurements of the Cross Section for e+e- -> hadrons at Center-of-Mass Energies from 2 to 5 GeV

    Get PDF
    We report values of R=σ(e+e−→hadrons)/σ(e+e−→μ+μ−)R = \sigma(e^+e^-\to {hadrons})/\sigma(e^+e^-\to\mu^+\mu^-) for 85 center-of-mass energies between 2 and 5 GeV measured with the upgraded Beijing Spectrometer at the Beijing Electron-Positron Collider.Comment: 5 pages, 3 figure

    The evolution of the topology of the ENG.

    No full text
    <p>(a) shows the node degree of the ENG. (b) shows the node strength of the ENG. (c) shows the betweenness centrality of the ENG. (d) shows the closeness centrality of the ENG. (e) shows the node occupation layer of the ENG. (f) shows the clustering coefficient of the ENG.</p

    The dynamic threshold of the CSI 300 two-tier industry index network.

    No full text
    <p>The dynamic threshold of the CSI 300 two-tier industry index network.</p

    Panel data model estimation results.

    No full text
    <p>Panel data model estimation results.</p

    ADF, Ljung-Box and ARCH effect test results for the ENG (CSI 300 Energy index) and the CSI 300 index returns.

    No full text
    <p>ADF, Ljung-Box and ARCH effect test results for the ENG (CSI 300 Energy index) and the CSI 300 index returns.</p

    Does network topology influence systemic risk contribution? A perspective from the industry indices in Chinese stock market - Fig 3

    No full text
    <p>MSTs of the CSI 300 two-tier industry index network on January 4, 2007 (a) and September 30, 2016(b).</p
    • …
    corecore