The game of go as a complex network

We study the game of go from a complex network perspective. We construct a directed network using a suitable definition of tactical moves including local patterns, and study this network for different datasets of professional tournaments and amateur games. The move distribution follows Zipf's law and the network is scale free, with statistical peculiarities different from other real directed networks, such as e. g. the World Wide Web. These specificities reflect in the outcome of ranking algorithms applied to it. The fine study of the eigenvalues and eigenvectors of matrices used by the ranking algorithms singles out certain strategic situations. Our results should pave the way to a better modelization of board games and other types of human strategic scheming.Comment: 6 pages, 9 figures, final versio

Scalar-tensor propagation of light in the inner solar system at the millimetric level

In a recent paper [1], motivated by forthcoming space experiments involving propagation of light in the Solar System, we have proposed an extention of the IAU metric equations at the c-4 level in General Relativity. However, scalar-tensor theories may induce corrections numerically comparable to the c-4 general relativistic terms. Accordingly, one first proposes in this paper an extension of [1] to the scalar-tensor case. The case of a hierarchized system (such as the Solar system) is emphasized. In this case, the relevant metric solution is proposed. Then, the geodesic solution relevant for propagation of light in the inner solar system at the millimetric level is given in explicit form.Comment: 18 pages, This article can be regarded as an extension of "eprint arXiv:1003.1889

Relativistic analysis of an earth-satellite time transfer

Analytical treatment of time transfer problem for Earth-Satellite system is presented. The development was made in a complete relativistic framework. In accordance with modern clock precision and for low altitude orbits, we neglect the other bodies and consider only the 1/c^2 Earth potential developed up to the J_2 term in spherical harmonics.Comment: 4 pages, conferenc

U.S. Greenfield Investments and M&A location: impact of American continental integration and Insider vs. Outsider position

This study examines the effects of economic integration on Greenfield Investments and cross-border Acquisitions locations. We use panel data on U.S. FDI in NAFTA and MERCOSUR members from 1989 to 1998. Economic integration is captured through tariff barriers and dummy variables. We pool data to distinguish between both agreements. We control for traditional macroeconomic determinants. It is found that economic integration certainly played a major role on U.S. firmsÕ location patterns. The U.S. position regarding the two agreements Ð insider vs. outsider- seemed to matter. Moreover, both our empirical study and our theoretical model underline the relevance of separating entry modes.FDI, integration, location, mode of entry

Loop equations from differential systems

To any differential system $d\Psi=\Phi\Psi$ where $\Psi$ belongs to a Lie group (a fiber of a principal bundle) and $\Phi$ is a Lie algebra $\mathfrak g$ valued 1-form on a Riemann surface $\Sigma$, is associated an infinite sequence of "correlators" $W_n$ that are symmetric $n$-forms on $\Sigma^n$. The goal of this article is to prove that these correlators always satisfy "loop equations", the same equations satisfied by correlation functions in random matrix models, or the same equations as Virasoro or W-algebra constraints in CFT.Comment: 20 page