ar X iv : c s / 05 03 01 2 v 1 [ cs . D B ] 4 M ar 2 00 5 First - order Complete and Computationally Complete Query Languages for Spatio - Temporal Databases

ar X iv : c s . D B / 0 50 30 12 v 2 7 M ar 2 00 5 First - order Complete and Computationally Complete Query Languages for Spatio - Temporal Databases 1

We address a fundamental question concerning spatio-temporal database systems: “What are exactly spatio-temporal queries?” We define spatio-temporal queries to be computable mappings that are also generic, meaning that the result of a query may only depend to a limited extent on the actual internal representation of the spatio-temporal data. Genericity is defined as invariance under groups of g...

ar X iv : c s / 01 10 03 8 v 1 [ cs . C C ] 1 8 O ct 2 00 1 Counting Is Easy †

For any fixed k, a remarkably simple single-tape Turing machine can simulate k independent counters in real time.

ar X iv : m at h / 05 04 08 2 v 4 [ m at h . D G ] 1 5 A pr 2 00 6 COMPLETE PROJECTIVE CONNECTIONS

The first examples of complete projective connections are uncovered: on surfaces, normal projective connections whose geodesics are all closed and embedded are complete. On manifolds of any dimension, normal projective connections induced from complete affine connections with slowly decaying positive Ricci curvature are complete.

ar X iv : h ep - p h / 05 12 03 9 v 1 2 D ec 2 00 5 November 2005 Status of the Cabibbo Angle

We review the recent experimental and theoretical progress in the determination of |V ud | and |V us |, and the status of the most stringent test of CKM unitarity. Future prospects on |V cd | and |V cs | are also briefly discussed.

ar X iv : h ep - p h / 04 05 03 9 v 1 5 M ay 2 00 4 η , η ′ → π + π − γ with coupled channels