637 research outputs found
Place of manufacture diversification in cyclical development of the enterprise
The relevance of the researched problem is caused by the fact that diversification is one of the best options for reforming enterprises. The aim of the research: to consider changes in production of outputs in development cycles of the enterprise. This will help to reveal the nature of manufacture diversification. The leading method to the research of this problem is the system approach, which allows to elicit factors promoting formation of business mechanism of manufacture diversification under the conditions of volatile economic environment. The results of the research are: it is offered to enhance the existing classification of enterprises by nomenclative and technological characteristic, taking into account the specific nature of processing capacity. The materials of the research can be useful for control bodies of enterprises when taking constructive steps in the sphere of manufacture diversification and strategy development. © 2016 Erofeev and Smolin
Ideal-Modified Bosonic Gas Trapped in an Arbitrary Three Dimensional Power-Law Potential
We analyze the effects caused by an anomalous single-particle dispersion
relation suggested in several quantum-gravity models, upon the thermodynamics
of a Bose-Einstein condensate trapped in a generic 3-dimensional power-law
potential. We prove that the shift in the condensation temperature, caused by a
deformed dispersion relation, described as a non-trivial function of the number
of particles and the shape associated to the corresponding trap, could provide
bounds for the parameters associated to such deformation. Additionally, we
calculate the fluctuations in the number of particles as a criterium of
thermodynamic stability for these systems. We show that the apparent
instability caused by the anomalous fluctuations in the thermodynamic limit can
be suppressed considering the lowest energy associated to the system in
question.Comment: 10 pages. arXiv admin note: text overlap with arXiv:1202.380
Bounce Conditions in f(R) Cosmologies
We investigate the conditions for a bounce to occur in
Friedmann-Robertson-Walker cosmologies for the class of fourth order gravity
theories. The general bounce criterion is determined and constraints on the
parameters of three specific models are given in order to obtain bounces
solutions. It is found that unlike the case of General Relativity, a bounce
appears to be possible in open and flat cosmologies.Comment: 11 pages LaTe
The linearization of the Kodama state
We study the question of whether the linearization of the Kodama state around
classical deSitter spacetime is normalizable in the inner product of the theory
of linearized gravitons on deSitter spacetime. We find the answer is no in the
Lorentzian theory. However, in the Euclidean theory the corresponding
linearized Kodama state is delta-functional normalizable. We discuss whether
this result invalidates the conjecture that the full Kodama state is a good
physical state for quantum gravity with positive cosmological constant.Comment: 14 pages, statement on the corresponding Yang-Mills case correcte
Unification of gravity, gauge fields, and Higgs bosons
We consider a diffeomorphism invariant theory of a gauge field valued in a
Lie algebra that breaks spontaneously to the direct sum of the spacetime
Lorentz algebra, a Yang-Mills algebra, and their complement. Beginning with a
fully gauge invariant action -- an extension of the Plebanski action for
general relativity -- we recover the action for gravity, Yang-Mills, and Higgs
fields. The low-energy coupling constants, obtained after symmetry breaking,
are all functions of the single parameter present in the initial action and the
vacuum expectation value of the Higgs.Comment: 12 pages, no figures. v2 minor correction
Continuous distribution of frequencies and deformed dispersion relations
The possibilities that, in the realm of the detection of the so--called
deformed dispersion relation, a light source with a continuous distribution of
frequencies offers is discussed. It will be proved that the presence of finite
coherence length entails the emergence of a new term in the interference
pattern. This is a novel trait, which renders a new possibility in the quest
for bounds associated with these deformed dispersion relations.Comment: Accepted in Classical and Quantum Gravit
Gravity from a fermionic condensate of a gauge theory
The most prominent realization of gravity as a gauge theory similar to the
gauge theories of the standard model comes from enlarging the gauge group from
the Lorentz group to the de Sitter group. To regain ordinary Einstein-Cartan
gravity the symmetry must be broken, which can be accomplished by known
quasi-dynamic mechanisms. Motivated by symmetry breaking models in particle
physics and condensed matter systems, we propose that the symmetry can
naturally be broken by a homogenous and isotropic fermionic condensate of
ordinary spinors. We demonstrate that the condensate is compatible with the
Einstein-Cartan equations and can be imposed in a fully de Sitter invariant
manner. This lends support, and provides a physically realistic mechanism for
understanding gravity as a gauge theory with a spontaneously broken local de
Sitter symmetry.Comment: 16 page
Quantizing speeds with the cosmological constant
Considering the Barrett-Crane spin foam model for quantum gravity with
(positive) cosmological constant, we show that speeds must be quantized and we
investigate the physical implications of this effect such as the emergence of
an effective deformed Poincare symmetry.Comment: 4 pages, revtex4, 3 figure
Bounce behaviour in Kantowski-Sachs and Bianchi Cosmologies
Many cosmological scenarios envisage either a bounce of the universe at early
times, or collapse of matter locally to form a black hole which re-expands into
a new expanding universe region. Energy conditions preclude this happening for
ordinary matter in general relativistic universes, but scalar or dilatonic
fields can violate some of these conditions, and so could possibly provide
bounce behaviour. In this paper we show that such bounces cannot occur in
Kantowski-Sachs models without violating the {\it reality condition}
. This also holds true for other isotropic spatially
homogenous Bianchi models, with the exception of closed
Friedmann-Robertson-Walker and Bianchi IX models; bounce behaviour violates the
{\em weak energy condition} and . We turn to the
Randall-Sundrum type braneworld scenario for a possible resolution of this
problem.Comment: Matches published versio
Reconstructing Quantum Geometry from Quantum Information: Spin Networks as Harmonic Oscillators
Loop Quantum Gravity defines the quantum states of space geometry as spin
networks and describes their evolution in time. We reformulate spin networks in
terms of harmonic oscillators and show how the holographic degrees of freedom
of the theory are described as matrix models. This allow us to make a link with
non-commutative geometry and to look at the issue of the semi-classical limit
of LQG from a new perspective. This work is thought as part of a bigger project
of describing quantum geometry in quantum information terms.Comment: 16 pages, revtex, 3 figure
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