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A. Posiewnik

Publications and source records attributed to A. Posiewnik.

2 recordsLinked to original sources

Quantum morphogenesis: A variation on Thom's catastrophe theory

Non-commutative propositions are characteristic of both quantum and non-quantum (sociological, biological, psychological) situations. In a Hilbert space model states, understood as correlations between all the possible propositions, are represented by density matrices. If systems in question interact via feedback with environment their dynamics is nonlinear. Nonlinear evolutions of density matrices lead to phenomena of morphogenesis which may occur in non-commutative systems. Several explicit exactly solvable models are presented, including `birth and death of an organism' and `development of complementary properties'.

quant-ph

What happens to spin during the SO(3)->SE(2) contraction? (On spin and extended structures in quantum mechanics)

It is shown that the spin operator can be described by an algebra which is in between so(3) and e(2). Relativistic version of the singlet state for two Dirac electrons is discussed. It is shown that a measure of massless particle's extension can be naturally constructed and that this measure corresponds at the classical level to the radius of the Robinson congruence.

quant-ph