The problem of characterising the accuracy of, and disturbance caused by a joint measurement of position and momentum is investigated. In a previous paper the problem was discussed in the context of the unbiased measurements considered by Arthurs and Kelly. It is now shown, that suitably modified versions of these results hold for a much larger class of simultaneous measurements. The approach i...

Introduction The principle somewhat vaguely formulated by Frege (see above) and called ‘Parmenides Principle’ in a not published manuscript by Pavel Tichý, can be interpreted in two mutually complementing ways. First – the way exploited by Frege and Tichý – an expression cannot be said to speak about something without denoting (naming) this something; an analysis of an expression must not conta...

The Correspondence Principle is the relation, which exists in certain economic models, between comparative statics of equilibria and the properties of out-of-equilibrium dynamics. The Correspondence Principle (CP) implies that one obtains unambiguous comparative statics by selecting equilibria with desirable dynamic properties. Generally, the CP determines comparative statics in models with a o...

The human body is a constant flux of thousands of chemical/biological interactions and processes connecting molecules, cells, organs, and fluids, throughout the brain, body, and nervous system. Up until recently it was thought that all these interactions operated in a linear sequence, passing on information much like a runner passing the baton to the next runner. However, the latest findings in...