21,278 research outputs found

    Charged black rings in supergravity with a single non-zero gauge field

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    General charged black ring solution with two angular momenta, a charge and a dipole charge is found by the inverse scattering method. The solution is presented in a relatively concise form in which its symmetries are manifest. The regularity conditions are found and the physical characteristics of the regular solution are expressed via its parameters.Comment: Misprints corrected, references added, JHEP forma

    d+idd+id Holographic Superconductors

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    A holographic model of d+idd+id superconductors based on the action proposed by Benini, Herzog, and Yarom [arXiv:1006.0731] is studied. This model has a charged spin two field in an AdS black hole spacetime. Working in the probe limit, the normalizable solution of the spin two field in the bulk gives rise to a d+idd+id superconducting order parameter at the boundary of the AdS. We calculate the fermion spectral function in this\ superconducting background and confirm the existence of fermi arcs for non-vanishing Majorana couplings. By changing the relative strength Îł\gamma of the dd and idid condensations, the position and the size of the fermi arcs are changed. When Îł=1\gamma =1, the spectrum becomes isotropic and the spectral function is s-wave like. By changing the fermion mass, the fermi momentum is changed. We also calculate the conductivity for these holographic d+idd+id superconductors where time reversal symmetry has been broken spontaneously. A non-vanishing Hall conductivity is obtained even without an external magnetic field.Comment: 24 pages,17 figures, Add more discussions on hall conductivity, two new figures, Matched with published versio

    Fermion correlators in non-abelian holographic superconductors

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    We consider fermion correlators in non-abelian holographic superconductors. The spectral function of the fermions exhibits several interesting features such as support in displaced Dirac cones and an asymmetric distribution of normal modes. These features are compared to similar ones observed in angle resolved photoemission experiments on high T_c superconductors. Along the way we elucidate some properties of p-wave superconductors in AdS_4 and discuss the construction of SO(4) superconductors.Comment: 49 pages, 11 figure

    Photoluminescence and lasing characteristics of single nonpolar GaN microwires

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    Domain Wall Holography for Finite Temperature Scaling Solutions

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    We investigate a class of near-extremal solutions of Einstein-Maxwell-scalar theory with electric charge and power law scaling, dual to charged IR phases of relativistic field theories at low temperature. These are exact solutions of theories with domain wall vacua; hence, we use nonconformal holography to relate the bulk and boundary theories. We numerically construct a global interpolating solution between the IR charged solutions and the UV domain wall vacua for arbitrary physical choices of Lagrangian parameters. By passing to a conformal frame in which the domain wall metric becomes that of AdS, we uncover a generalized scale invariance of the IR scaling solution, indicating a connection to the physics of Lifshitz fixed points. Finally, guided by effective field theoretic principles and the physics of nonconformal D-branes, we argue for the applicability of domain wall holography even in theories with AdS critical points, namely those theories for which a scalar potential is dominated by a single exponential term over a large range

    Holographic Superconductors with Power-Maxwell field

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    With the Sturm-Liouville analytical and numerical methods, we investigate the behaviors of the holographic superconductors by introducing a complex charged scalar field coupled with a Power-Maxwell field in the background of dd-dimensional Schwarzschild AdS black hole. We note that the Power-Maxwell field takes the special asymptotical solution near boundary which is different from all known cases. We find that the larger power parameter qq for the Power-Maxwell field makes it harder for the scalar hair to be condensated. We also find that, for different qq, the critical exponent of the system is still 1/2, which seems to be an universal property for various nonlinear electrodynamics if the scalar field takes the form of this paper.Comment: 14 pages, 1 figure, and 2 table

    Flavor brane on the baryonic branch of moduli space

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    We study an extra flavor in the cascading SU((k+1)M)xSU(k M) gauge theory by adding probe D7-brane to the geometry. By finding a solution to the kappa-symmetry equation we establish that the D7-brane is mutually supersymmetric with the background everywhere on the baryonic branch of moduli space. We also discuss possible applications of this result.Comment: 15 pages; v2 typo corrected, references adde

    Holographic Correlation Functions for Open Strings and Branes

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    In this paper, we compute holographically the two-point and three-point functions of giant gravitons with open strings. We consider the maximal giant graviton in S5S^5 and the string configurations corresponding to the ground states of Z=0 and Y=0 open spin chain, and the spinning string in AdS5_5 corresponding to the derivative type impurities in Y=0 or Z=0 open spin chain as well. We treat the D-brane and open string contribution separately and find the corresponding D3-brane and string configurations in bulk which connect the composite operators at the AdS5_5 boundary. We apply a new prescription to treat the string state contribution and find agreements for the two-point functions. For the three-point functions of two giant gravitons with open strings and one certain half-BPS chiral primary operator, we find that the D-brane contributions to structure constant are always vanishing and the open string contribution for the Y=0 ground state is in perfect match with the prediction in the free field limit.Comment: 25 page

    Virologically confirmed population-based burden of hospitalization caused by influenza a and b among children in Hong Kong

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    Background. We sought to determine the virologically confirmed hospitalization rates associated with influenza virus infection among Hong Kong children. Methods. Patients <18 years of age who lived on Hong Kong Island (a separate island within Hong Kong) and were admitted to either of the only 2 public hospitals on the island for a febrile acute respiratory infection on 1 fixed day of the week in each hospital from October 2003 through September 2006 were prospectively recruited. These 2 hospitals together accounted for 72.5% of all general pediatric admissions in Hong Kong Island with a known population denominator. Nasopharyngeal aspirates were obtained from all recruited patients and were tested for influenza A and influenza B viruses by direct antigen detection and culture. Results. All cases of influenza A during 2003-2004 were caused by H3N2 virus, whereas 85.7% of cases during 2004-2005 were due to H3N2 virus, and 93.5% during 2005-2006 were due to H1N1 virus. During 2004-2005, infants <1 year of age had the highest rate of hospitalization for influenza A (103.8 cases per 10,000 population), whereas children 1 year of age had the highest rate of hospitalization during the other 2 seasons (95.5 and 54.6 cases per 10,000 population during 2003-2004 and 2005-2006, respectively). A protection rate of 25%, presumably attributable to maternal antibodies, was seen in infants <1 year of age who were hospitalized during 2003-2004 with infection due to an H3N2 virus that had been in circulation. The hospitalization rates for influenza B were highest among children 2-4 years of age. Conclusions. This population-based study of hospitalizations due to virologically confirmed influenza demonstrated a very high burden of disease among young children in Hong Kong. The morbidity varied with virus type, subtype, and antigenic variants. © 2009 by the Infectious Diseases Society of America. All rights reserved.published_or_final_versio

    Pseudo-Killing Spinors, Pseudo-supersymmetric p-branes, Bubbling and Less-bubbling AdS Spaces

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    We consider Einstein gravity coupled to an n-form field strength in D dimensions. Such a theory cannot be supersymmetrized in general, we nevertheless propose a pseudo-Killing spinor equation and show that the AdS X Sphere vacua have the maximum number of pseudo-Killing spinors, and hence are fully pseudo-supersymmetric. We show that extremal p-branes and their intersecting configurations preserve fractions of the pseudo-supersymmetry. We study the integrability condition for general (D,n) and obtain the additional constraints that are required so that the existence of the pseudo-Killing spinors implies the Einstein equations of motion. We obtain new pseudo-supersymmetric bubbling AdS_5 X S^5 spaces that are supported by a non-self-dual 5-form. This demonstrates that non-supersymmegtric conformal field theories may also have bubbling states of arbitrary droplets of free fermions in the phase space. We also obtain an example of less-bubbling AdS geometry in D=8, whose bubbling effects are severely restricted by the additional constraint arising from the integrability condition.Comment: typos corrected, extra comments and references added, version appeared in JHE
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