Bittersweet (Tax) Symphony

The increased globalization has given rise to many new opportunities for companies to conduct their business. Companies reach out, far beyond the boundaries of their home state. However, conducting business abroad leads to a plethora of tax rules which a company should take into account. They are no longer limited to the tax legislation of their home state, but the companies should also adhere to the tax laws applicable in the state where they conduct their business. This may lead to the undesired effect of double taxation. In order to prevent this effect, many countries have signed tax treaties through which they allocate taxing. The interface of a variety of domestic legislations and tax treaties leads to higher compliance costs to companies, but many companies have been able to utilize the rules to severely limit their tax liability.

Duality relation between coherence and path information in the presence of quantum memory

The wave-particle duality demonstrates a competition relation between wave and particle behavior for a particle going through an interferometer. This duality can be formulated as an inequality, which upper bounds the sum of interference visibility and path information. However, if the particle is entangled with a quantum memory, then the bound may decrease. Here, we find the duality relation between coherence and path information for a particle going through a multipath interferometer in the presence of a quantum memory, offering an upper bound on the duality relation which is directly connected with the amount of entanglement between the particle and the quantum memory.Comment: 6 pages, 1 figure, comments are welcom

Tax Seminar I on Relevant Issues Related to the Permanent Establishment in the Light of the OECD Model Tax Convention on Income and Capital

A tax seminar for students following the LL.M course in International and European Tax Law was held at the Faculty of Arts and Social Sciences of Maastricht University on 11 December, 2013. The objective of this seminar was to provide the students with additional information and insights on the permanent establishment (PE) concept in preparation for their upcoming exam and, at the same time, give them a deeper understanding of the current developments in this area. Dr Marcel Schaper, assistant professor of law at Maastricht University, welcomed the speakers as well as the participating students and gave a brief introduction to the subject of the seminar. The seminar featured two presentations given by Mr Andreas Perdelwitz, principal research associate in the International Bureau of Fiscal Documentation (IBFD) European Knowledge Group, and Ms Oana Popa, senior research associate in the IBFD.

Reply to "Comment on `Generalized James' effective Hamiltonian method'"

In the preceding Comment [1] it was claimed that the third-order Hamiltonian obtained in our original paper [2] is not Hermitian for general situations when considering time-dependence and the way of deriving the effective third-order expansion is not very rigorous. To reply the comment we should emphasize the following three points: first of all, the third-order Hamiltonian given in our paper is exactly Hermitian under the conditions mentioned there. Secondly, the iterative method adopted in our paper to derive the generalized effective Hamiltonian is equivalent to the Dyson series, and its correctness can thus be guaranteed. Thirdly, although the truncated effective Hamiltonian is indeed non-Hermitian under the time-dependent situation as presented in the Comment, it corresponds exactly to the non-unitary truncated Dyson series. Considering the truncated Dyson series has been extensively utilized in the time-dependent perturbation theory, in our opinion, the non-Hermitian truncated effective Hamiltonian can still be treated as an approximation of the effective Hamiltonian.Comment: 9 page