36,733 research outputs found
Sustainable business models: integrating employees, customers and technology
This Special Issue of the Journal of Business & Industrial Marketing has the same title as the 23rd International Conference CBIM 2018 (June 18-20, 2018, Madrid, Spain) “Sustainable Business Models: Integrating Employees, Customers and Technology”. In this edition of International Conference, following a competitive blind review process, papers from 126 authors and 25 countries were ultimately accepted. The best papers of the Conference were invited to submit to this Special Issue and we were also open to direct submissions from other authors.
We present here the 17 accepted papers for publication in this Special Issue
The Critical Point of Unoriented Random Surfaces with a Non-Even Potential
The discrete model of the real symmetric one-matrix ensemble is analyzed with
a cubic interaction. The partition function is found to satisfy a recursion
relation that solves the model. The double-scaling limit of the recursion
relation leads to a Miura transformation relating the contributions to the free
energy coming from oriented and unoriented random surfaces. This transformation
is the same kind as found with a cuartic interaction.Comment: 20p (Frontpage included
The space-time symmetry group of a spin 1/2 elementary particle
The space-time symmetry group of a model of a relativistic spin 1/2
elementary particle, which satisfies Dirac's equation when quantized, is
analyzed. It is shown that this group, larger than the Poincare group, also
contains space-time dilations and local rotations. It has two Casimir
operators, one is the spin and the other is the spin projection on the body
frame. Its similarities with the standard model are discussed. If we consider
this last spin observable as describing isospin, then, this Dirac particle
represents a massive system of spin 1/2 and isospin 1/2. There are two possible
irreducible representations of this kind of particles, a colourless or a
coloured one, where the colour observable is also another spin contribution
related to the zitterbewegung. It is the spin, with its twofold structure, the
only intrinsic property of this Dirac elementary particle.Comment: Contribution to the JINR(Dubna) SPIN05 workshop, 18 pages, 1 figure.
Abstract and minor changes of sections 2 to
Is General Relativity a simpler theory?
Gravity is understood as a geometrization of spacetime. But spacetime is also
the manifold of the boundary values of the spinless point particle in a
variational approach. Since all known matter, baryons, leptons and gauge bosons
are spinning objects, it means that the manifold, which we call the kinematical
space, where we play the game of the variational formalism of an elementary
particle is greater than spacetime. This manifold for any mechanical system is
a Finsler metric space such that the variational formalism can always be
interpreted as a geodesic problem on this space. This manifold is just the flat
Minkowski space for the free spinless particle. Any interaction modifies its
flat Finsler metric as gravitation does. The same thing happens for the
spinning objects but now the Finsler metric space has more dimensions and its
metric is modified by any interaction, so that to reduce gravity to the
modification only of the spacetime metric is to make a simpler theory, the
gravitational theory of spinless matter. Even the usual assumption that the
modification of the metric only involves dependence of the metric coefficients
on the spacetime variables is also a restriction because in general these
coefficients are dependent on the velocities. In the spirit of unification of
all forces, gravity cannot produce, in principle, a different and simpler
geometrization than any other interaction.Comment: 10 pages 1 figure, several Finsler metric examples and a conclusion
section added. Minor correction
Resolved Hubble Space spectroscopy of ultracool binary systems
Using the low-resolution mode of the Space Telescope Imaging Spectrograph
(STIS) aboard the \emph{Hubble Space Telescope} (HST), we have obtained
spatially resolved spectra of 20 ultracool dwarfs. 18 of them belong to 9 known
very low-mass binary systems with angular separations in the range 0.37-0.098
arcseconds. We have derived spectral types in the range dM7.5 to dL6 from the
PC3 index, and by comparing our STIS spectra with ground-based spectra of
similar spectral resolution from Mart{\'\i}n et al. (1999). We have searched
for H emission in each object but it was clearly detected in only 2 of
them. We find that the distribution of H emission in our sample is
statistically different from that of single field dwarfs, suggesting an
intriguing anticorrelation between chromospheric activity and binarity for
M7--M9.5 dwarfs. We provide measuments of the strength of the main photospheric
features and the PC3 index, and we derive calibrations of spectral subclasses
versus F814W and K-band absolute magnitudes for a subset of 10 dwarfs in 5
binaries that have known trigonometric parallaxes.Comment: accepted for publication in A&
Influence of general convective motions on the exterior of isolated rotating bodies in equilibrium
The problem of describing isolated rotating bodies in equilibrium in General
Relativity has so far been treated under the assumption of the circularity
condition in the interior of the body. For a fluid without energy flux, this
condition implies that the fluid flow moves only along the angular direction,
i.e. there is no convection. Using this simplification, some recent studies
have provided us with uniqueness and existence results for asymptotically flat
vacuum exterior fields given the interior sources. Here, the generalisation of
the problem to include general sources is studied. It is proven that the
convective motions have no direct influence on the exterior field, and hence,
that the aforementioned results on uniqueness and existence of exterior fields
apply equally in the general case.Comment: 8 pages, LaTex, uses iopart style files. To appear in Class. Quatum
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