A Study on CRM Implementation in Chinese Commercial Banks

The paper first presents the theory of Customer Relationship Management (CRM) under E-commerce circumstances. It then focuses on the motives and obstructions in implementing CRM in Chinese commercial banks. Further, the paper puts forward a trial solution to these specific problems to be a solving aid to Chinese commercial banks under Customer Relationship Management

On Higher Derivative Couplings in Theories with Sixteen Supersymmetries

We give simple arguments for new non-renormalization theorems on higher derivative couplings of gauge theories to supergravity, with sixteen supersymmetries, by considerations of brane-bulk superamplitudes. This leads to some exact results on the effective coupling of D3-branes in type IIB string theory. We also derive exact results on higher dimensional operators in the torus compactification of the six dimensional (0, 2) superconformal theory.Comment: 31 pages, 10 figures, section 2 reconstructured, new result in section 3.2, additional clarifications adde

(2,2) Superconformal Bootstrap in Two Dimensions

We find a simple relation between two-dimensional BPS N=2 superconformal blocks and bosonic Virasoro conformal blocks, which allows us to analyze the crossing equations for BPS 4-point functions in unitary (2,2) superconformal theories numerically with semidefinite programming. We constrain gaps in the non-BPS spectrum through the operator product expansion of BPS operators, in ways that depend on the moduli of exactly marginal deformations through chiral ring coefficients. In some cases, our bounds on the spectral gaps are observed to be saturated by free theories, by N=2 Liouville theory, and by certain Landau-Ginzburg models.Comment: 56 pages, 14 figure

Supersymmetry Constraints and String Theory on K3

We study supervertices in six dimensional (2,0) supergravity theories, and derive supersymmetry non-renormalization conditions on the 4- and 6-derivative four-point couplings of tensor multiplets. As an application, we obtain exact non-perturbative results of such effective couplings in type IIB string theory compactified on K3 surface, extending previous work on type II/heterotic duality. The weak coupling limit thereof, in particular, gives certain integrated four-point functions of half-BPS operators in the nonlinear sigma model on K3 surface, that depend nontrivially on the moduli, and capture worldsheet instanton contributions.Comment: 47 pages, 4 figure

Little String Amplitudes (and the Unreasonable Effectiveness of 6D SYM)

We study tree level scattering amplitudes of four massless states in the double scaled little string theory, and compare them to perturbative loop amplitudes in six-dimensional super-Yang-Mills theory. The little string amplitudes are computed from correlators in the cigar coset CFT and in N=2 minimal models. The results are expressed in terms of integrals of conformal blocks and evaluated numerically in the alpha' expansion. We find striking agreements with up to 2-loop scattering amplitudes of massless gluons in 6D SU(k) SYM at a Z_k invariant point on the Coulomb branch. We comment on the issue of UV divergence at higher loop orders in the gauge theory and discuss the implication of our results.Comment: 58 pages, 5 figures, 3 tables, comments added, references adde

Topological Defect Lines and Renormalization Group Flows in Two Dimensions

We consider topological defect lines (TDLs) in two-dimensional conformal field theories. Generalizing and encompassing both global symmetries and Verlinde lines, TDLs together with their attached defect operators provide models of fusion categories without braiding. We study the crossing relations of TDLs, discuss their relation to the 't Hooft anomaly, and use them to constrain renormalization group flows to either conformal critical points or topological quantum field theories (TQFTs). We show that if certain non-invertible TDLs are preserved along a RG flow, then the vacuum cannot be a non-degenerate gapped state. For various massive flows, we determine the infrared TQFTs completely from the consideration of TDLs together with modular invariance.Comment: 101 pages, 63 figures, 2 tables; v3: minor changes, added footnotes and references, published versio

Determination of Outflow Properties for the Quasi-thermal Radiation-Dominated Gamma-Ray Bursts

Some gamma-ray bursts (GRBs) are observed with prompt phase changing from quasi-thermal to non-thermal emission. The quasi-thermal emission is always well described by a multi-color blackbody function, and based on this modeling, a characteristic temperature with corresponding flux is taken as a probe to diagnose the magnetization properties of the central engine with the `top-down' approach proposed by Gao \& Zhang. Furthermore, the initial radius of the acceleration for the outflow as well as the magnetization parameter ($\sigma_0$) could be constrained to within a narrower range than those with a pair of temperature and flux from modeling with a single blackbody plus an empirical function (BAND function or exponential cut-off power law). We apply this method to some bursts with known emission properties, such as GRB 210121A from a typical pure hot fireball and GRB 210610B from a hybrid jet. It is found that this method works well on these control samples. With this method, we find it is suggestive that the photospheric emission of GRB 221022B is mainly from a fireball, rather than from a hybrid jet, while the non-thermal component is caused by internal shock (IS) mechanism, due to the increasing Lorentz Factor with time.Comment: 9 pages, 3 figures, submitted to ApJ on 06-May-202