3,439 research outputs found
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 zeitunabhĂ€ngige Optionen via Internet im Vordergrund stehen. Im Beitrag werden die Teilprozesse fĂŒr Abstimmungen (eVoting) und Wahlen (eElection) im Detail erlĂ€utert. Die Identifikation und Authentifikation des WĂ€hlers erfolgt in der Phase der Registrierung, in einer zweiten Phase muss die elektronische Stimmabgabe fĂŒr Abstimmungen und Wahlen anonym erfolgen. Danach gelangen mehrdimensionale Visualisierungstechniken zur Darstellung der Ab-stimmungs- und Wahlergebnisse zur Anwendung (ePosting). Das politische und kulturelle GedĂ€chtnis (Public Memory), im eGovernment auf Portalen und mit digitalen Archiven realisiert, erweitert die Optionen einer Informations- und Wissensgesellschaft und lĂ€sst 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
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