Do Mobile Pensioners Threaten the Deferred Taxation of Savings?

We investigate optimal taxation of lifetime income with and without an emigration option during old age. The government sets the rates of deferred taxation and of possibly reduced taxation of interest. If agents are immobile, the optimal policy consists in full deferral of income taxes on savings and a full taxation of interest. Mobility of the old calls for lower degrees of deferral and reduced taxation of interest. However, the optimum never entails full immediate taxation of savings in combination with full tax exemption on capital income.deferred taxation, income tax, savings, migration

A Team Based Variant of CTL

We introduce two variants of computation tree logic CTL based on team semantics: an asynchronous one and a synchronous one. For both variants we investigate the computational complexity of the satisfiability as well as the model checking problem. The satisfiability problem is shown to be EXPTIME-complete. Here it does not matter which of the two semantics are considered. For model checking we prove a PSPACE-completeness for the synchronous case, and show P-completeness for the asynchronous case. Furthermore we prove several interesting fundamental properties of both semantics.Comment: TIME 2015 conference version, modified title and motiviatio

The model checking fingerprints of CTL operators

The aim of this study is to understand the inherent expressive power of CTL operators. We investigate the complexity of model checking for all CTL fragments with one CTL operator and arbitrary Boolean operators. This gives us a fingerprint of each CTL operator. The comparison between the fingerprints yields a hierarchy of the operators that mirrors their strength with respect to model checking

Elektronische Abstimmungen und Wahlen

Zusammenfassungen: Bei elektronischen Abstimmungen und Wahlen gibt es eine Vielzahl von Lösungen, wobei ortsund zeitunabhängige Optionen via Internet im Vordergrund stehen. Im Beitrag werden die Teilprozesse für Abstimmungen (eVoting) und Wahlen (eElection) im Detail erläutert. Die Identifikation und Authentifikation des Wählers erfolgt in der Phase der Registrierung, in einer zweiten Phase muss die elektronische Stimmabgabe für Abstimmungen und Wahlen anonym erfolgen. Danach gelangen mehrdimensionale Visualisierungstechniken zur Darstellung der Ab-stimmungs- und Wahlergebnisse zur Anwendung (ePosting). Das politische und kulturelle Gedächtnis (Public Memory), im eGovernment auf Portalen und mit digitalen Archiven realisiert, erweitert die Optionen einer Informations- und Wissensgesellschaft und lässt ein demokratisches Politcontrolling z

Theory of filtered type-II PDC in the continuous-variable domain: Quantifying the impacts of filtering

Parametric down-conversion (PDC) forms one of the basic building blocks for quantum optical experiments. However, the intrinsic multimode spectral-temporal structure of pulsed PDC often poses a severe hindrance for the direct implementation of the heralding of pure single-photon states or, for example, continuous-variable entanglement distillation experiments. To get rid of multimode effects narrowband frequency filtering is frequently applied to achieve a single-mode behavior. A rigorous theoretical description to accurately describe the effects of filtering on PDC, however, is still missing. To date, the theoretical models of filtered PDC are rooted in the discrete-variable domain and only account for filtering in the low gain regime, where only a few photon pairs are emitted at any single point in time. In this paper we extend these theoretical descriptions and put forward a simple model, which is able to accurately describe the effects of filtering on PDC in the continuous-variable domain. This developed straightforward theoretical framework enables us to accurately quantify the trade-off between suppression of higher-order modes, reduced purity and lowered Einstein-Podolsky-Rosen (EPR) entanglement, when narrowband filters are applied to multimode type-II PDC.Comment: 15 pages, 13 figure

A hit-and-run Giant Impact scenario

The formation of the Moon from the debris of a slow and grazing giant impact of a Mars-sized impactor on the proto-Earth (Cameron & Ward 1976, Canup & Asphaug 2001) is widely accepted today. We present an alternative scenario with a hit-and-run collision (Asphaug 2010) with a fractionally increased impact velocity and a steeper impact angle.Comment: 11 pages, 2 figures, in press in ICARUS note