We discuss the fate of certain tachyonic closed string theories from two perspectives. In both cases our approach involves studying directly configurations with finite negative treelevel cosmological constant. Closed string analogues of orientifolds, which carry negative tension, are argued to represent the minima of the tachyon potential in some cases. In other cases, we make use of the fact, ...

The technique presented in this paper allows the automatic construction of a lumped Markov chain for almost symmetrical Stochastic Well-formed Net (SWN) models. The starting point is the Extended Symbolic Reachability Graph (ESRG), which is a reduced representation of a SWN model reachability graph (RG), based on the aggregation of states into classes. These classes may be used as aggregates fo...

just like any other economic field, housing market has two basic foundations which are demand and supply. its obvious that disequilibrum between these foundations, will drasticaly affect the housing affordability and can also lead to wide slump in many markets. that’s why, policy makers usually intend to stimulat the supply by means of providing low intrest loans, low priced land, etc. in this ...

We use matrix model results to investigate the Sine-Gordon model coupled to two dimensional gravity. For relevant (in the RG sense) potentials, we show that the c = 1 string, which appears in the ultraviolet limit of this model, flows to a set of decoupled c = 0 (pure gravity) models in the infrared. The torus partition sum, which was argued previously to count the number of string degrees of f...

Groundwater is connected to the landscape above and is thus affected by the overlaying land uses. This study evaluated the impacts of land uses upon groundwater quality using trilinear analysis. Trilinear analysis is a display of experimental data in a triangular graph. Groundwater quality data collected from agricultural, septic tank, forest, and wastewater land uses for a 6-year period were u...

This study examines fertility variation across housing types and childbearing patterns following housing changes. While the effect of family changes on housing choices has been studied in detail, little is known about childbearing patterns within various housing types, and this despite the fact that many studies suggest housing to be an important determinant of fertility. We use longitudinal re...

Unrenormalizable theories contain infinitely many free parameters. Considering these theories in terms of the Wilsonian renormalization group (RG), we suggest a method for removing this large ambiguity. Our basic assumption is the existence of the maximal ultraviolet cutoff in a cutoff theory, and we require that the theory be so fine-tuned as to reach the maximal cutoff. The theory so obtained...

We consider C/ZN and C/ZN orbifolds of heterotic string theories and ZN orbifolds of AdS3. We study theories with N=2 worldsheet superconformal invariance and construct RG flows. Following Harvey, Kutasov, Martinec and Moore, we compute gcl and show that it decreases monotonically along RG flowsas conjectured by them. For the heterotic string theories, the gauge degrees of freedom do not contri...

1. introduction the phenomenon of land consolidation has been the concern of economists, geographers, soil scientists, anthropologists, and politician in the last decades. it has achieved little success for agricultural development in iran. most of iranian land consolidation schemes ignore to meet sustainability criteria as a critical phase in the planning process. therefore, they have caused m...