Elliptic Gromov-Witten Invariants And Virasoro Conjecture

The Virasoro conjecture proposed by Eguchi-Hori-Xiong and S. Katz predicts that the generating function of Gromov-Witten invariants is annihilated by infinitely many differential operators which form a half branch of the Virasoro algebra. In this paper, we study the genus-1 case of the conjecture. In particular, we will give some necessary and sufficient conditions for the genus-1 Virasoro conjecture.Comment: 40 pages, LaTex file, minor modifications, new addres

Quantum product on the big phase space and the Virasoro conjecture

We first study the quantum product on the big phase space defined by gravitational Gromov-Witten invariants. We then use this product to give an interpretation for various topological recursion relations and also use it to study the Virasoro conjecture proposed by Eguchi-Hori-Xiong and Katz. We will give a recursive formulation to the Virasoro conjecture and study properties of relevent vector fields, which will be useful in proving and applying the Virasoro conjecture for all genera. In the genus-2 case, we will prove that the genus-2 Virasoro conjecture can be reduced to the $L_{1}$ constraint for any manifold. In the case when the quantum cohomology of the underlying manifold is not too degenerate (in particular, is semisimple) we will prove an explicit formula expressing the generating function of genus-2 Gromov-Witten invariants in terms of genus-0 and genus-1 data. This result reduces the genus-2 Virasoro conjecture to a genus-1 problem for such manifolds.Comment: LaTex file, 53 page

Exploring key determinants of virtual worlds \ud business success based on users' experience and\ud perception

Given the growth and popularity of virtual worlds, companies have a\ud strong interest in presenting themselves successfully in virtual worlds. We\ud designed an experimental study to identify the key determinants of virtual worlds\ud business success based on users’ experience and perception. The preliminary\ud results indicate that Starbucks, McDonalds, and Paris are the 3 most favorite sites.\ud Furthermore, 5 key determinants (entertainment, functionality, interactivity,\ud reality, and sociality) of business success in virtual worlds are identified in this\ud study. We conclude the practical and theoretical implications of the findings of\ud this study.\u

Fiscal decentralization and political centralization in China

"While, politically speaking, China has a centralized government structure with strong top-down mandates, under the country’s current fiscal system, local governments are responsible for providing most local public goods and services. Large differences in economic structures and revenue bases exist, however, causing the implicit tax rate and fiscal burdens in support of local government functions to vary significantly across jurisdictions. Regions initially endowed with a broader nonfarm tax base do not need to rely heavily on new and existing firms to finance public goods provision, which creates a healthy investment environment in support of nonfarm sector growth. In contrast, local governments in regions where agriculture is the major economic activity spend the majority of their resources on their own operating costs, leaving little for public investment. Because of the relatively high transaction costs associated with collecting taxes from the agricultural sector, local governments tend to levy the existing nonfarm sector heavily, thereby greatly inhibiting its growth. As a result, regional differences in economic structures and fiscal dependent burdens may translate into widening gaps in equality. " Authors' AbstractNonfarm sector ,Regional economics ,Inequality ,