Loop quantization of the Gowdy model with local rotational symmetry

We provide a full quantization of the vacuum Gowdy model with local rotational symmetry. We consider a redefinition of the constraints where the Hamiltonian Poisson-commutes with itself. We then apply the canonical quantization program of loop quantum gravity within an improved dynamics scheme. We identify the exact solutions of the constraints and the physical observables, and we construct the physical Hilbert space. It is remarkable that quantum spacetimes are free of singularities. New quantum observables naturally arising in the treatment partially codify the discretization of the geometry. The preliminary analysis of the asymptotic future/past of the evolution indicates that the existing Abelianization technique needs further refinement.Comment: 19 pages, 1 fi

Caravel — new coronary microcatheter

W artykule zostały zaprezentowane techniczne właściwości nowego mikrocewnika wieńcowego Caravel firmy Asahi. Jest to cewnik cienkościenny, hydrofilny, zakończony stożkową końcówką, o dobrej manewrowalności i łatwo pokonujący zmiany miażdżycowe.In the paper technical characteristics of the new coronary microcatheter Caravel manufactured by Asahi company was presented. Caravel is a thin-wall, hydrophilic, with tapered tip and good maneuverability catheter, easily passing through the atherosclerotic lesions