| 1. |
- Yakovlev, D. G., et al.
(författare)
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Lev Landau and the concept of neutron stars
- 2013
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Ingår i: Physics Uspekhi. - : Turpion Ltd.. - 1063-7869 .- 1468-4780. ; 56:3, s. 289-295
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Forskningsöversikt (refereegranskat)abstract
- We review Lev Landau's role in the history of neutron star physics in the 1930s. According to the recollections of Rosenfeld (Proc. 16th Solvay Conference on Physics, 1974, p. 174), Landau improvised the concept of neutron stars in a discussion with Bohr and Rosenfeld just after the news of the discovery of the neutron reached Copenhagen in February 1932. We present arguments that the discussion must have taken place in March 1931, before the discovery of the neutron, and that they, in fact, discussed the paper written by Landau in Zurich in February 1931 but not published until February 1932 (Phys. Z. Sowjetunion 1, 285). In this paper, Landau mentioned the possible existence of dense stars that look like one giant nucleus; this could be regarded as an early theoretical prediction or anticipation of neutron stars, albeit prior to the discovery of the neutron. The coincidence of the dates of the neutron discovery and the publication of the paper has led to an erroneous association of Landau's paper with the discovery of the neutron. In passing, we outline Landau's contribution to the theory of white dwarfs and to the hypothesis of stars with neutron cores.
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| 2. |
- Kavoulakis, Georgios, et al.
(författare)
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Rapidly rotating Bose-Einstein condensates in anharmonic potentials
- 2003
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Ingår i: New Journal of Physics. - : IOP Publishing. - 1367-2630. ; 5
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Tidskriftsartikel (refereegranskat)abstract
- Rapidly rotating Bose-Einstein condensates confined in anharmonic traps can exhibit a rich variety of vortex phases, including a vortex lattice, a vortex lattice with a hole, and a giant vortex. Using an augmented Thomas - Fermi variational approach to determine the ground state of the condensate in the rotating frame - valid for sufficiently strongly interacting condensates - we determine the transitions between these three phases for a quadratic- plus- quartic confining potential. Combining the present results with previous numerical simulations of small rotating condensates in such anharmonic potentials, we delineate the general structure of the zero-temperature phase diagram.
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| 3. |
- Kavoulakis, Georgios, et al.
(författare)
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Rotating Bose-Einstein condensates with attractive interactions
- 2004
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Ingår i: Physical Review A (Atomic, Molecular and Optical Physics). - 1050-2947. ; 70:4
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Tidskriftsartikel (refereegranskat)abstract
- We examine the phase diagram of a Bose-Einstein condensate of atoms, interacting with an attractive pseudopotential, in a quadratic-plus-quartic potential trap rotating at a given rate. Investigating the behavior of the gas as a function of interaction strength and rotational frequency of the trap, we find that the phase diagram has three distinct phases: one with vortex excitation, one with center-of-mass excitation, and an unstable phase in which the gas collapses.
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