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.
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 .
6976924
(Non)-supersymmetric Marginal Deformations from Twistor String Theory
The tree-level amplitudes in the β-deformed supersymmetric gauge theory are derived from twistor string theory. We first show that a simple generalization of [M. Kulaxizi, K. Zoubos, Marginal deformations of N=4 SYM from open/closed twistor strings, Nucl. Phys. B 738 (2006) 317, hep-th/0410122] gives us the desired results for all the tree-level amplitudes up to first order in the deformation parameter β. Then we provide a new proposal which matches field theory to all orders of β. With our deformed twistor string theory, it can be shown that integration over connected instantons and disconnected instantons remain equivalent. The tree-level amplitudes in the non-supersymmetric γ-deformed theory can be obtained using a similar deformation of the twistor string. Finally, we find improved twistor string results for the tree-level purely gluonic amplitudes in theories with more general marginal deformations.
119542604
Comments on two loop four particle amplitude in superstring theory
It is shown that the four-particle amplitude of superstring theory at two loops obtained in [1], [2] is equivalent to the previously obtained results in [3]-[5]. Here the 2 symmetry in hyperelliptic Riemann surface plays an important role in the proof.
1525151
MHV vertices and scattering amplitudes in gauge theory
The generic googly amplitudes in gauge theory are computed by using the Cachazo-Svrcek-Witten approach to perturbative calculation in gauge theory and the results are in agreement with the previously well-known ones. Within this approach we also discuss the parity transformation, charge conjugation and the dual Ward identity. We also extend this calculation to include fermions and the googly amplitudes with a single quark-anti-quark pair are obtained correctly from fermionic MHV vertices. At the end we briefly discuss the possible extension of this approach to gravity.
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.
119522047
Lattice calculation of nucleon axial form factors
Abstract Preliminary results on the isovector and isoscalar axial-vector form factors of the proton from a lattice QCD calculation are presented and discussed. The results are based on a quenched 16 3 × 24 lattice at β = 6.0 with Wilson fermions at κ = 0.152. Results from the smeared source are compared with those from the point source. It is found that the smeared source gives somewhat better results at zero momentum transfer but worse results at high momentum transfers. Our results also suggest that the quark loop contribution to the flavor-singlet axial-vector current may play an important role in understanding the quark-spin content of the proton as determined from the recent EMC experiment.
119219715
Dynamics of tachyon field in spatially curved FRW universe
The dynamics of a tachyon field plus a barotropic fluid is investigated in spatially curved FRW universe. We perform a phase-plane analysis and obtain scaling solutions accompanying with a discussion on their stability. Furthermore, we construct the form of scalar potential which may give rise to stable solutions for spatially open and closed universe separately.
117395921
An analytical study of the O(N) nonlinear sigma models on lattice
In the variational cumulant expansion approach, we calculate the internal energy for the d-dimensional O(N) nonlinear a models on lattice. Specially, me give the results for two-dimensional O(3), O(4) and O(5) models. A comparison with Monte-Carlo (MC) data is also presented. Our formalism can given the results for O(N) nonlinear cr models (for any N and any dimensionality d) straightforwardly.
119203647
Dipole coupling effect of holographic fermion in the background of charged Gauss-Bonnet AdS black hole
A bstractWe investigate the holographic fermions in the charged Gauss-Bonnet AdSd black hole background with the dipole coupling between fermion and gauge field in the bulk. We show that in addition to the strength of the dipole coupling, the spacetime dimension and the higher curvature correction in the gravity background also influence the onset of the Fermi gap and the gap distance. We find that the higher curvature effect modifies the fermion spectral density and influences the value of the Fermi momentum for the appearance of the Fermi surface. There are richer physics in the boundary fermion system due to the modification in the bulk gravity.
119695474
Recursions in Calogero-Sutherland Model Based on Virasoro Singular Vectors
The present work is much motivated by finding an explicit way in the construction of the Jack symmetric function, which is the spectrum generating function for the Calogero-Sutherland (CS) model. To accomplish this work, the hidden Virasoro structure in the CS model is much explored. In particular, we found that the Virasoro singular vectors form a skew hierarchy in the CS model. Literally, skew is analogous to coset, but here specifically refer to the operation on the Young tableaux. In fact, based on the construction of the Virasoro singular vectors, this hierarchical structure can be used to give a complete construction of the CS states, i.e. the Jack symmetric functions, recursively. The construction is given both in operator formalism as well as in integral representation. This new integral representation for the Jack symmetric functions may shed some insights on the spectrum constructions for the other integrable systems.