We investigate brane world models in higher-derivative gravity theories where the gravitational Lagrangian is an arbitrary function of the Ricci scalar. Making use of the conformal equivalence of such gravity models and Einstein-Hilbert gravity with a scalar field, we deduce the main features of higher-derivative gravity brane worlds. We solve for a gravity model that has corrections quadratic ...

The metropolitan area is an important carrier to enhance regional innovation capacity and soft power. There are always some imbalances in the dynamic process of regional development, for example, the metropolitan “lamp shadow” phenomenon. In this paper, we take the first nature and the second nature as research perspectives and construct a theoretical framework to analyze the “lamp shadow” phen...

In this paper, Steam Assisted Gravity Drainage (SAGD) is introduced and its advantages over ordinary steam injection is demonstrated. A simple simulation model is built and three scenarios of natural production, ordinary steam injection, and SAGD are compared in terms of their cumulative oil production and cumulative oil steam ratio. The results show that SAGD can significantly enhance oil prod...

We consider brane-induced gravity model in more than one extra dimensions, regularized by assuming that the bulk gravity is soft in ultraviolet. We study linear theory about flat multi-dimensional space-time and flat brane. We first find that this model allows for violation of equivalence between gravitational and inertial masses of brane matter. We then observe that the model has a scalar ghos...

We study self-consistent cosmological solutions for an Einstein Universe in a graphbased induced gravity model. The graph-based field theory has been proposed by the present authors to generalize dimensional deconstruction. In this paper, we consider self-consistent Einstein equations for a “graph theory space”. Especially, we demonstrate specific results for cycle graphs. 1 Pre-history 1.1 Ind...

We show how a Metric Affine theory of Dilaton gravity can be reduced to an effective Riemannian Dilaton gravity model. A simple generalization of the Obukhov-Tucker-Wang theorem to Dilaton gravity is then presented. 04.20.-q, 04.40.-b, 04.50.+h, 04.62.+v [email protected]

Drawing on a new and comprehensive measure of logistics quality, our gravity model suggests logistics in the exporting and partner-country can have an important impact on bilateral exports. A one standard deviation improvement in the exporter’s logistics quality, which for example would improve Gabon to the level of Guinea, would raise exports by almost 60%. Landlocked countries’ exports depend...