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Niels Bohr
Rodrigo Sierra Lozada
Acta Universitaria , 2012,
Abstract: García- Colín S. Leopoldo, Mazari Marcos, Moshinsky Marcos, et.al., Niehls Bohr: Científico, Filósofo, Humanista, México: (SEP; FCE; CONACYT), 2002. (Colección La Ciencia desde México; 14).
The Bohr superconductor  [PDF]
J. E. Hirsch
Physics , 2015,
Abstract: Superconductors have often been described as `giant atoms'. The simplest description of atoms that heralded their quantum understanding was proposed by Bohr in 1913. The Bohr atom starts from some simple assumptions and deduces that the angular momentum of the electron in Bohr orbits is quantized in integer units of $\hbar$. This remarkable result, which does not appear to be implicit in the assumptions of the model, can be interpreted as a `theoretical proof' of the model's validity to describe physical reality at some level. Similarly we point out here that from some simple assumptions it can be deduced that electrons in superconductors reside in mesoscopic orbits with orbital angular momentum $\hbar/2$. This implies that both in superconductors and in ferromagnets the long-range order results from elementary units of identical angular momentum. Similarly to the case of the Bohr atom we propose that this remarkable result is compelling evidence that this physics, which is not part of conventional BCS theory, describes physical reality at some level and heralds a qualitatively new understanding of superconductors.
Niels Bohr y la bomba atómica
Bes,Daniel R;
Revista SAAP , 2011,
Abstract: the aim of this work is to temporarily correlate the scientific discoveries that allowed the construction of the atomic bomb, with the political events and technological implementations that took place at the relevant countries. the danish physicist niels bohr -who had been the senior leader in the construction of quantum mechanics- was the first to realize that nuclear arms were qualitatively different from any other weapon used so far, and that the construction of a stable postwar peace required an opening on the nuclear subject between the allied countries, including the ussr. in spite of bohr's high level contacts within the usa and great britain governments, bohr's ideas took over gradually, only after his death.
Rejection of the Light Quantum: The Dark Side of Niels Bohr  [PDF]
Luis J. Boya
Physics , 2002, DOI: 10.1023/B:IJTP.0000005976.75253.ca
Abstract: Evidence is recalled of the strong opposition of Niels Bohr, at the time of the Old Quantum Theory 1.913-25, to the Lichtquanten hypothesis of Einstein. Some episodes with H.A. Kramers, J.C. Slater and W. Heisenberg are recollected; Bohr's changing point of view is traced back to some philosophical antecedents and to his endeavour to deduce quantum results from the Correspondence Principle. Some consequences for the future interpretation of Quantum Mechanics, specially to the Complementarity Principle, are considered.
Bohr Hamiltonian with deformation-dependent mass term  [PDF]
Dennis Bonatsos,P. Georgoudis,D. Lenis,N. Minkov,C. Quesne
Physics , 2009, DOI: 10.1016/j.physletb.2009.12.049
Abstract: The Bohr Hamiltonian describing the collective motion of atomic nuclei is modified by allowing the mass to depend on the nuclear deformation. Exact analytical expressions are derived for spectra and wave functions in the case of a gamma-unstable Davidson potential, using techniques of supersymmetric quantum mechanics. Numerical results in the Xe-Ba region are discussed.
Reconciling a component and process view  [PDF]
Maria Spichkova,Heinz Schmidt
Computer Science , 2015,
Abstract: In many cases we need to represent on the same abstraction level not only system components but also processes within the system, and if for both representation different frameworks are used, the system model becomes hard to read and to understand. We suggest a solution how to cover this gap and to reconcile component and process views on system representation: a formal framework that gives the advantage of solving design problems for large-scale component systems.
Bohr space in six dimensions  [PDF]
P. E. Georgoudis
Physics , 2013, DOI: 10.1016/j.physletb.2014.02.026
Abstract: A conformal factor in the Bohr model embeds Bohr space in six dimensions, revealing the $O(6)$ symmetry and its contraction to the $E(5)$ at infinity. Phenomenological consequences are discussed after the re-formulation of the Bohr Hamiltonian in six dimensions on a five sphere.
Bohr's inequality revisited  [PDF]
Masatoshi Fujii,Mohammad Sal Moslehian,Jadranka Micic
Mathematics , 2011,
Abstract: We survey several significant results on the Bohr inequality and presented its generalizations in some new approaches. These are some Bohr type inequalities of Hilbert space operators related to the matrix order and the Jensen inequality. An eigenvalue extension of Bohr's inequality is discussed as well.
EMBRACE@Nancay: An Ultra Wide Field of View Prototype for the SKA  [PDF]
S. A. Torchinsky,A. O. H. Olofsson,B. Censier,A. Karastergiou,M. Serylak,P. Renaud,C. Taffoureau
Physics , 2015,
Abstract: A revolution in radio receiving technology is underway with the development of densely packed phased arrays for radio astronomy. This technology can provide an exceptionally large field of view, while at the same time sampling the sky with high angular resolution. Such an instrument, with a field of view of over 100 square degrees, is ideal for performing fast, all-sky, surveys, such as the "intensity mapping" experiment to measure the signature of Baryonic Acoustic Oscillations in the HI mass distribution at cosmological redshifts. The SKA, built with this technology, will be able to do a billion galaxy survey. I will present a very brief introduction to radio interferometry, as well as an overview of the Square Kilometre Array project. This will be followed by a description of the EMBRACE prototype and a discussion of results and future plans.
Ultra deep sub-kpc view of nearby massive compact galaxies  [PDF]
Ignacio Trujillo,Eleazar R. Carrasco,Anna Ferre-Mateu
Physics , 2012, DOI: 10.1088/0004-637X/751/1/45
Abstract: Using Gemini North telescope ultra deep and high resolution (sub-kpc) K-band adaptive optics imaging of a sample of 4 nearby (z~0.15) massive (~10^{11}M_sun) compact (R<1.5 kpc) galaxies, we have explored the structural properties of these rare objects with an unprecedented detail. Our surface brightness profiles expand over 12 magnitudes in range allowing us to explore the presence of any faint extended envelope on these objects down to stellar mass densities ~10^{6} M_sun/kpc^{2} at radial distances of ~15 kpc. We find no evidence for any extended faint tail altering the compactness of these galaxies. Our objects are elongated, resembling visually S0 galaxies, and have a central stellar mass density well above the stellar mass densities of objects with similar stellar mass but normal size in the present universe. If these massive compact objects will eventually transform into normal size galaxies, the processes driving this size growth will have to migrate around 2-3x10^{10}M_sun stellar mass from their inner (R<1.7 kpc) region towards their outskirts. Nearby massive compact galaxies share with high-z compact massive galaxies not only their stellar mass, size and velocity dispersion but also the shape of their profiles and the mean age of their stellar populations. This makes these singular galaxies unique laboratories to explore the early stages of the formation of massive galaxies.
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