Comment on the new AdS universe

We show that Bonnor's new Anti-de Sitter (AdS) universe and its D-dimensional generalization is the previously studied AdS soliton.Comment: 2 pages; version 2: major changes including the titl

The Effect of Tax Treaties on Multinational Firms: New Evidence from Microdata

This paper uses affiliate level data from Swedish multinationals to examine the impact of tax treaties on both overall affiliate sales and the composition of those sales. In line with previous results, we find little evidence for an effect of treaties on the level of total sales. We do, however, find that a tax treaty increases the probability of investment by a firm in a given country. In addition, we find that a treaty reduces exports to the parent but increases imports of intermediate inputs from the parent. This is consistent with treaties increasing the effective host tax. This suggests that tax treaties impact the behavior of multinationals along some dimensions but not along others.Tax Treaties; Multinational Firms; Foreign Direct Investment

Green's Matrix for a Second Order Self-Adjoint Matrix Differential Operator

A systematic construction of the Green's matrix for a second order, self-adjoint matrix differential operator from the linearly independent solutions of the corresponding homogeneous differential equation set is carried out. We follow the general approach of extracting the Green's matrix from the Green's matrix of the corresponding first order system. This construction is required in the cases where the differential equation set cannot be turned to an algebraic equation set via transform techniques.Comment: 19 page

Newtonian Counterparts of Spin 2 Massless Discontinuities

Massive spin 2 theories in flat or cosmological ($\Lambda \ne 0$) backgrounds are subject to discontinuities as the masses tend to zero. We show and explain physically why their Newtonian limits do not inherit this behaviour. On the other hand, conventional ``Newtonian cosmology'', where $\Lambda$ is a constant source of the potential, displays discontinuities: e.g. for any finite range, $\Lambda$ can be totally removed.Comment: 6 pages, amplifies the ``Newtonian cosmology'' analysis. To appear as a Class. Quantum Grav. Lette

Problems With Complex Actions

We consider Euclidean functional integrals involving actions which are not exclusively real. This situation arises, for example, when there are $t$-odd terms in the the Minkowski action. Writing the action in terms of only real fields (which is always possible), such terms appear as explicitly imaginary terms in the Euclidean action. The usual quanization procedure which involves finding the critical points of the action and then quantizing the spectrum of fluctuations about these critical points fails. In the case of complex actions, there do not exist, in general, any critical points of the action on the space of real fields, the critical points are in general complex. The proper definition of the function integral then requires the analytic continuation of the functional integration into the space of complex fields so as to pass through the complex critical points according to the method of steepest descent. We show a simple example where this procedure can be carried out explicitly. The procedure of finding the critical points of the real part of the action and quantizing the corresponding fluctuations, treating the (exponential of the) complex part of the action as a bounded integrable function is shown to fail in our explicit example, at least perturbatively.Comment: 6+epsilon pages, no figures, presented at Theory CANADA