117894041
Supersymmetric AdS3 × S2 M-theory geometries with fluxes
Motivated by a recent observation that the LLM geometries admit 1/4-BPS M5-brane probes with worldvolume AdS3 × Σ2 × S1 preserving the R-symmetry, SU(2) × U(1), we initiate a classification of the most general AdS3×S2 geometries in M-theory dual to two-dimensional chiral $$ \mathcal{N} = \left( {4,0} \right) $$ SCFTs. We retain all field strengths consistent with symmetry and derive the torsion conditions for the internal six-manifold, M6, in terms of two linearly independent spinors. Surprisingly, we identify three Killing directions for M6, but only two of these generate isometries of the overall ansatz. We show that the existence of this third direction depends on the norm of the spinors. With the torsion conditions derived, we establish the MSW solution as the only solution in the class where M6 is an SU(3)-structure manifold. Then, specialising to the case where the spinors define an SU(2)-structure, we note that supersymmetry dictates that all magnetic fluxes necessarily thread the S2. Finally, by assuming that the two remaining Killing directions are parallel and aligned with one of the two vectors defining the SU(2)-structure, we derive a general relationship for the two spinors before extracting a known class of solutions from the torsion conditions.
119222618
Spin-3 topologically massive gravity
Abstract In this Letter, we study the spin-3 topologically massive gravity (TMG), paying special attention to its properties at the chiral point. We propose an action describing the higher spin fields coupled to TMG. We discuss the traceless spin-3 fluctuations around the AdS 3 vacuum and find that there is an extra local massive mode, besides the left-moving and right-moving boundary massless modes. At the chiral point, such extra mode becomes massless and degenerates with the left-moving mode. We show that at the chiral point the only degrees of freedom in the theory are the boundary right-moving graviton and spin-3 field. We conjecture that spin-3 chiral gravity with generalized Brown–Henneaux boundary condition is holographically dual to 2D chiral CFT with classical W 3 algebra and central charge c R = 3 l / G .
118600500
On the generality of the LLM geometries in M-theory
In this note we revisit the Lin, Lunin, Maldacena (LLM) class of d = 11 supergravity solutions with symmetry SO(6) × SO(3) × R, but generalise to allow for all fluxes consistent with the isometries. Using the Killing spinor equation, we prove there are no supersymmetric geometries with additional fluxes beyond the LLM ansatz. In addition, the LLM relationship between Killing spinors, ϵ− = − γ5ϵ+, may be seen as a consequence of identifying two Killing directions identified through the Killing spinor equation corresponding to candidate R-symmetry directions.
119210702
Multi-Spin Strings in AdS_4*CP^3 and its \beta-deformations
In this paper, we study the multi-spin string solutions in AdS_4*CP^3 and its \beta-deformation with real \beta. We give various explicit solutions after some general studies. Conserved charges are computed for these explicit solutions.
16908302
Supersymmetric Wilson loops in N = 6 super-ChernSimons-matter theory
Abstract We study supersymmetric Wilson loop operators in ABJM theory from both sides of the AdS 4 / CFT 3 correspondence. We first construct some supersymmetric Wilson loops. The perturbative computations are performed in the field theory side at the first two orders. A fundamental string solution ending on a circular loop is also studied.
17857935
SIX-QUARK AMPLITUDES FROM FERMIONIC MHV VERTICES
The fermionic extension of the CSW approach to perturbative gauge theory coupled with fermions is used to compute the six-quark QCD amplitudes. We find complete agreement with the results obtained by using the usual Feynman rules.
16931057
A Statistical Analysis of Point-like Sources in the Chandra Galactic Center Survey ∗
The Chandra Galactic Center Survey detected similar to 800 X-ray point-like sources in the 2 degrees x 0.8 degrees sky region around the Galactic Center. We study the spatial and luminosity distributions of these sources according to their spectral properties. Fourteen bright sources detected are used to fit jointly an absorbed power-law model, from which the power-law photon index is determined to be similar to 2.5. Assuming that all other sources have the same power-law form, the relation between hardness ratio and HI column density N-H is used to estimate the NH values for all sources. Monte Carlo simulations show that these sources are more likely concentrated in the Galactic center region, rather than distributed throughout the Galactic disk. We also find that the luminosities of the sources are positively correlated with their HI column densities, i.e., a more luminous source has a higher HI column density. From this relation, we suggest that the X-ray luminosity comes from the interaction between an isolated old neutron star and interstellar medium (mainly dense molecular clouds). Using the standard Bondi accretion theory and the statistical information of molecular clouds in the Galactic center, we confirm this positive correlation and calculate the luminosity range in this scenario, which is consistent with the observation (10(32)-10(35) erg s(-1)).
118493008
Holographic fermionic system with dipole coupling on Q-lattice
A bstractWe construct a holographic model for a fermionic system on Q-lattice and compute the spectral function in the presence of a dipole coupling. Both key features of doped Mott insulators, the dynamical generation of a gap and spectral weight transfer, are observed when adjusting the value of the coupling parameter p. Of particular interest is that when the background is in a deep insulating phase, the Mott gap opens much easier with a smaller coupling parameter in comparison with a metallic background. The effects of lattice parameters on the width of the gap Δ/μ are studied and a turning point is observed near the critical regime of metal-insulator transitions of the background. Furthermore, the temperature dependence of the spectral function is studied. Finally, we also observe that the anisotropic Q-lattice generates anisotropic peaks with different magnitudes, indicating that insulating and metallic phases arise in different directions.
39742923
Metal-insulator transition by holographic charge density waves.
We construct a gravity dual for charge density waves (CDWs) in which the translational symmetry along one spatial direction is spontaneously broken. Our linear perturbation calculation on the gravity side produces the frequency dependence of the optical conductivity, which exhibits the two familiar features of CDWs, namely, the pinned collective mode and gapped single-particle excitation. These two features indicate that our gravity dual also provides a new mechanism to implement the metal to insulator phase transition by CDWs, which is further confirmed by the fact that dc conductivity decreases with the decreased temperature below the critical temperature.
122217753
THE BOUND STATE EQUATION FOR TWO GLUONS AND ITS SOLUTION
We derive the bound state equation for two gluons in relativistic quantum field theory, i.e. the Bethe–Salpeter (BS) equation for two gluons. To solve it, we choose the kernel as the sum of a one-gluon exchange potential, a contact interaction and a linear confining potential. Under instantaneous approximation, this BS equation is solved numerically. The spectrum and the BS wave function of the glueballs are obtained in this framework. The numerical results are in agreement with that of recent lattice calculation.
119192598
Evidence for a new Sigma* resonance with J**P = 1/2- in the old data of K- p ---> Lambda pi+ pi- reaction
Distinctive patterns are predicted by quenched quark models and unquenched quark models for the lowest SU(3) baryon nonet with spin parity J P = 1/2 - . While the quenched quark models predict the lowest 1/2- ∑* resonance to be above 1600 MeV, the unquenched quark models predict it to be around ∑*(1385) energy. Here we reexamine some old data of the K - p → ∧π + π - reaction and find that besides the well-established ∑*(1385) with J p = 3/2 + , there is indeed some evidence for the possible existence of a new ∑* resonance with J P = 1/2- around the same mass but with broader decay width. Higher statistic data on relevant reactions are needed to clarify the situation.