Analysis of constraints and their algebra in bimetric theory

We perform a canonical analysis of the bimetric theory in the metric formulation, computing the constraints and their algebra explicitly. In particular, we compute a secondary constraint, that has been argued to exist earlier, and show that it has the correct form to eliminate the ghost. We also identify a set of four first class constraints that generate the algebra of general covariance. The covariance algebra naturally determines a spacetime metric for the theory. However, in bimetric theory, this metric is not unique but depends on how the first class constraints are identified.Comment: 36 pages; v2: minor improvements, reference adde

SOLIDARITET, INDIVIDUALISME OG DEMOKRATI

I et demokrati bestemmer vi alle på lige fod, efter princippet én person, én stemme, men derefter må vi alle bøje os for flertallet. Dette system indebærer politisk solidaritet og udelukker individuel frihed, dvs. friheden til at gøre, som den enkelte ønsker. Tilsvarende indebærer den universelle velfærdsstat økonomisk solidaritet ved at sikre alle pleje, uddannelse og pension. Denne solidaritet udgør den økonomiske basis for demokratiets politiske solidaritet

Migrating Birds and Tickborne Encephalitis Virus

During spring and autumn 2001, we screened 13,260 migrating birds at Ottenby Bird Observatory, Sweden, and found 3.4% were infested with ticks. Four birds, each a different passerine species, carried tickborne encephalitis virus (TBEV)–infected ticks (Ixodes ricinus). Migrating birds may play a role in the geographic dispersal of TBEV-infected ticks