The star product technique translates the framework of local fields on noncommutative space–time into nonlocal fields on standard space– time. We consider the example of fields on κ– deformed Minkowski space, transforming under κ–deformed Poincaré group with noncommutative parameters. By extending the star product to the tensor

Cantor proved in 1874 [Cantor G (1874) J Reine Angew Math 77:258-262] that the continuum is uncountable, and Hilbert's first problem asks whether it is the smallest uncountable cardinal. A program arose to study cardinal invariants of the continuum, which measure the size of the continuum in various ways. By Gödel [Gödel K (1939) Proc Natl Acad Sci USA 25(4):220-224] and Cohen [Cohen P (1963) P...

We reinvestigate the radio pulsar "death lines" within the framework of two different types of the polar cap acceleration models, i.e., the vacuum gap model and the space-charge-limited flow model, with either curvature radiation or inverse Compton scattering photons as the source of pairs. General relativistic frame dragging is taken into account in both models. We find that the inverse Compto...

We present the results of a comprehensive, near-UV-to-near-IR Hubble Space Telescope WFC3 imaging study young planetary nebula (PN) NGC 6302, archetype class extreme bi-lobed, pinched-waist PNe that are rich in dust and molecular gas. The new emission-line image suite clearly defines dusty toroidal equatorial structure bisects 6302's polar lobes, fine structures (clumps, knots, filaments) withi...