Large N Limit of Non-Commutative Gauge Theories

Using the correspondence between gauge theories and string theory in curved backgrounds, we investigate aspects of the large $N$ limit of non-commutative gauge theories by considering gravity solutions with $B$ fields. We argue that the total number of physical degrees of freedom at any given scale coincides with the commutative case. We then compute a two-point correlation function involving momentum components in the directions of the $B$-field. In the UV regime, we find that the two-point function decays exponentially with the momentum. A calculation of Wilson lines suggests that strings cannot be localized near the boundary. We also find string configurations that are localized in a finite region of the radial direction. These are worldsheet instantons.Comment: 21 pages, harvmac. Some errors in correlators corrected, minor corrections to the Lorentzian solution

Social Prosperity Perception in Cultural Tourism Destinations: the Case of Peña de Bernal, Huejotzingo and Yuanhuitlán, México

The present quantitative study with a descriptive design tries to determine the conditions of "social prosperity" of three Mexican cultural tourist destinations, Yanhuitlán, Huejotzingo and Peña de Bernal. These places face similar conditions in aspects like marginalization and poverty but with activities like tourism have tried to reverse these adverse conditions. The objective was to know the perception of their population about the improvement of their living conditions as a result of the tourist activity through the application of surveys carried out in the chosen destinations. The instrument used was a questionnaire with a Likert scale to facilitate the response of the informants and the processing of the information. For the validity and reliability of the measurement instrument a factor reduction analysis and a Cronbach's alpha were elaborated, after which a one-way ANOVA was elaborated to know the differences of means taking the Bonferroni and Scheffe tests. The results show a significant difference between the averages of destinations in how residents perceive prosperity in the selected tourist destinations

Relative cyclic homology of square zero extensions

Let k be a characteristic zero field, C a k-algebra and M a square zero two sided ideal of C. We obtain a new mixed complex, simpler that the canonical one, giving the Hochschild and cyclic homologies of C relative to M. This complex resembles the canonical reduced mixed complex of an augmented algebra. We begin the study of our complex showing that it has a harmonic decomposition like to the one considered by Cuntz and Quillen for the normalized mixed complex of an algebra. We also give new proofs of two theorems of Goodwillie, obtaining an improvement of one of them.Comment: 24 pages. Definitive version, to appear in Crelle Journa