12,477 research outputs found
Near-field Electrodynamics of Atomically Doped Carbon Nanotubes
We develop a quantum theory of near-field electrodynamical properties of
carbon nanotubes and investigate spontaneous decay dynamics of excited states
and van der Waals attraction of the ground state of an atomic system close to a
single-wall nanotube surface. Atomic spontaneous decay exhibits vacuum-field
Rabi oscillations -- a principal signature of strong atom-vacuum-field
coupling. The strongly coupled atomic state is nothing but a 'quasi-1D cavity
polariton'. Its stability is mainly determined by the atom-nanotube van der
Waals interaction. Our calculations of the ground-state atom van der Waals
energy performed within a universal quantum mechanical approach valid for both
weak and strong atom-field coupling demonstrate the inapplicability of
conventional weak-coupling-based van der Waals interaction models in a close
vicinity of the nanotube surface.Comment: Book Chapter. 50 pages, 11 figures. To be published in "Nanotubes:
New Research", edited by F.Columbus (Nova Science, New York, 2005
Three-point Lie algebras and Grothendieck's dessins d'enfants
We define and classify the analogues of the affine Kac-Moody Lie algebras for
the ring corresponding to the complex projective line minus three points. The
classification is given in terms of Grothendieck's dessins d'enfants. We also
study the question of conjugacy of Cartan subalgebras for these algebras.Comment: 16 page
From Rent-Seeking Activities to Economic Activities: The Strategic Transformation of the Deregulated Firm
The political theory of regulation holds that deregulation of utilities obliges the former monopoly to abandon its rent-seeking activities to concentrate upon economic activities. However, the arguments presented by scholars to explain this strategic transformation are not entirely convincing. We argue in this paper that the role and the nature of the firm during the deregulation process have been underestimated in previous works. After describing the main steps of this process, we thus propose a dynamic explanation of the strategic transformation of the deregulated firm based on the concepts of firm capabilities, access to rents and transaction costs.rent-seeking; strategic renewal; capabilities
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