293 research outputs found
Das Beste aus zwei Welten Key Learnings aus dem ACTIVATR-Programm
Gerade innovative Startups drohen in allen Industrien die Geschäftsmodelle etablierter Unternehmen zu zerstören. Etablierte Unternehmen hingegen haben die nötigen Ressourcen und Netzwerke, um Geschäftsmodelle früh zu testen und schnell zu skalieren. Dieser Research Brief beantwortet daher die Frage, wie Vorteile aus der Corporate- und der Startup-Welt zum Zwecke erfolgreicher Innovationen verbunden werden können. Dazu werden Beobachtungen und Interviews aus einem mehrmonatigen Accelerator-Programm ausgewertet, welches bewusst Teams aus beiden Welten für eine Innovation Challenge kombiniert. Wir leiten Erkenntnisse ab für Entscheider aus etablierten Unternehmen, Startups sowie Accelerator-Programmen und zeigen, unter welchen Bedingungen eine erfolgreiche Kombination der Startup- und der Corporate-Logik möglich wird
Five-Dimensional Moving Brane Solutions with Four-Dimensional Limiting Behaviour
Under certain conditions some solutions to five-dimensional heterotic
M-theory can be accurately described by the four-dimensional action of the
theory - they have a four-dimensional limit. We consider the connection between
solutions of four and five-dimensional heterotic M-theory when moving
five-branes are present in the bulk. We begin by describing how to raise the
known four-dimensional moving brane solutions to obtain approximate solutions
to the five-dimensional theory, presenting for the first time the metric
template necessary for this procedure. We then present the first solutions to
the five-dimensional theory containing moving five-branes. We can then discuss
the connection between our new exact five-dimensional solution and the
four-dimensional ones. It is shown that our new solution corresponds to a
solution with a static brane in four-dimensions. In other words our new
solution could not have been identified as containing a moving brane from a
purely four-dimensional viewpoint.Comment: 18 pages, 6 figure
Assessment of numerical methods for fully resolved simulations of particle-laden turbulent flows
This work was granted access to the HPC resources of CALMIP and the National Center for Atmospheric Researchs (NCAR) supercomputing centers. P. Costa acknowledges the funding from the Portuguese Foundation for Science and Technology under grant no. SFRH/BD/85501/2012. L.-P. Wang acknowledges the funding from the U.S. National Science Foundation (NSF) under grants CBET-1706130.Peer reviewedPostprin
Heterotic M-Theory Cosmology in Four and Five Dimensions
We study rolling radii solutions in the context of the four- and
five-dimensional effective actions of heterotic M-theory. For the standard
four-dimensional solutions with varying dilaton and T-modulus, we find
approximate five-dimensional counterparts. These are new, generically
non-separating solutions corresponding to a pair of five-dimensional domain
walls evolving in time. Loop corrections in the four-dimensional theory are
described by certain excitations of fields in the fifth dimension. We point out
that the two exact separable solutions previously discovered are precisely the
special cases for which the loop corrections are time-independent. Generically,
loop corrections vary with time. Moreover, for a subset of solutions they
increase in time, evolving into complicated, non-separating solutions. In this
paper we compute these solutions to leading, non-trivial order. Using the
equations for the induced brane metric, we present a general argument showing
that the accelerating backgrounds of this type cannot evolve smoothly into
decelerating backgrounds.Comment: 15 pages, Latex, 1 eps figur
Transport, optical and electronic properties of the half metal CrO2
The electronic structure of CrO_2 is critically discussed in terms of the
relation of existing experimental data and well converged LSDA and GGA
calculations of the electronic structure and transport properties of this half
metal magnet, with a particular emphasis on optical properties. We find only
moderate manifestations of many body effects. Renormalization of the density of
states is not large and is in the typical for transition metals range. We find
substantial deviations from Drude behavior in the far-infrared optical
conductivity. These appear because of the unusually low energy of interband
optical transitions. The calculated mass renormalization is found to be rather
sensitive to the exchange-correlation functional used and varies from 10%
(LSDA) to 90% (GGA), using the latest specific heat data. We also find that
dressing of the electrons by spin fluctuations, because of their high energy,
renormalizes the interband optical transition at as high as 4 eV by about 20%.
Although we find no clear indications of strong correlations of the Hubbard
type, strong electron-magnon scattering related to the half metallic band
structure is present and this leads to a nontrivial temperature dependence of
the resistivity and some renormalization of the electron spectra.Comment: 9 Revtex 2 column pages, including 8 postscript figures. Two more
figures are included in the submission that are not embedded in the paper,
representing DOS and bandstructure of the paramagnetic CrO
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