4,009 research outputs found
Eating Your Own Cooking: The Impact of Social, Mobile, Analytics and Cloud Technologies at IBM
In its 100+ years of company history, IBM reinvented itself multiple times. In the last 20 years, IBM had shifted from individual products to integrated solutions and moved to become a globally integrated enterprise with standardized processes. In 2014, the expanding adoption of social, mobile, analytics, and cloud (SMAC) technologies generated excitement in the industry. IBM believed these technologies presented a huge growth opportunity. Simultaneously, management viewed SMAC technologies as disruptive forces demanding transformative changes to how IBM worked. And introducing new ways of working to 400,000 employees in 175 countries was a daunting task. Based on personal interviews with 17 IBM business and IT executives, the case illustrates organizational challenges of introducing current technologies that even providers of these technologies face – in other words, when they “eat their own cooking.” It demonstrates the difficulties large companies face when implementing technologies that students use daily and take for granted
Effective constraints of loop quantum gravity
Within a perturbative cosmological regime of loop quantum gravity corrections
to effective constraints are computed. This takes into account all
inhomogeneous degrees of freedom relevant for scalar metric modes around flat
space and results in explicit expressions for modified coefficients and of
higher order terms. It also illustrates the role of different scales
determining the relative magnitude of corrections. Our results demonstrate that
loop quantum gravity has the correct classical limit, at least in its sector of
cosmological perturbations around flat space, in the sense of perturbative
effective theory.Comment: 44 pages, 6 figure
Formation and Evolution of Structure in Loop Cosmology
Inhomogeneous cosmological perturbation equations are derived in loop quantum
gravity, taking into account corrections in particular in gravitational parts.
This provides a framework for calculating the evolution of modes in structure
formation scenarios related to inflationary or bouncing models. Applications
here are corrections to the Newton potential and to the evolution of large
scale modes which imply non-conservation of curvature perturbations possibly
noticeable in a running spectral index. These effects are sensitive to
quantization procedures and test the characteristic behavior of correction
terms derived from quantum gravity.Comment: 4 page
Mixed Higgsino Dark Matter from a Large SU(2) Gaugino Mass
We observe that in SUSY models with non-universal GUT scale gaugino mass
parameters, raising the GUT scale SU(2) gaugino mass |M_2| from its unified
value results in a smaller value of -m_{H_u}^2 at the weak scale. By the
electroweak symmetry breaking conditions, this implies a reduced value of \mu^2
{\it vis \`a vis} models with gaugino mass unification. The lightest neutralino
can then be mixed Higgsino dark matter with a relic density in agreement with
the measured abundance of cold dark matter (DM). We explore the phenomenology
of this high |M_2| DM model. The spectrum is characterized by a very large wino
mass and a concomitantly large splitting between left- and right- sfermion
masses. In addition, the lighter chargino and three light neutralinos are
relatively light with substantial higgsino components. The higgsino content of
the LSP implies large rates for direct detection of neutralino dark matter, and
enhanced rates for its indirect detection relative to mSUGRA. We find that
experiments at the LHC should be able to discover SUSY over the portion of
parameter space where m_{\tg} \alt 2350-2750 ~GeV, depending on the squark
mass, while a 1 TeV electron-positron collider has a reach comparable to that
of the LHC. The dilepton mass spectrum in multi-jet + \ell^+\ell^- + \eslt
events at the LHC will likely show more than one mass edge, while its shape
should provide indirect evidence for the large higgsino content of the decaying
neutralinos.Comment: 36 pages with 26 eps figure
Open Luttinger liquids
We study the problem of Luttinger liquids interacting with an active
environment. We are particularly interested in how dissipation affects the
response and correlation functions of non-isolated Luttinger liquids. We show
that the exchange of particles, energy, and momentum lead to changes in the
exponents characterizing the various correlations functions. We discuss the
importance of the zero mode physics in this context.Comment: Revtex, 4 pages. Final version published in PR
Hydrodynamic excitations of Bose condensates in anisotropic traps
The collective excitations of Bose condensates in anisotropic axially
symmetric harmonic traps are investigated in the hydrodynamic and Thomas-Fermi
limit. We identify an additional conserved quantity, besides the axial angular
momentum and the total energy, and separate the wave equation in elliptic
coordinates. The solution is reduced to the algebraic problem of diagonalizing
finite dimensional matrices. The classical quasi-particle dynamics in the local
density approximation for energies of the order of the chemical potential is
shown to be chaotic.Comment: 4 pages revtex including 1 table, and 1 figure in postscrip
On Yukawa quasi-unification with mu<0
Although recent data on the muon anomalous magnetic moment strongly disfavor
the constrained minimal supersymmetric standard model with mu<0, they cannot
exclude it because of theoretical ambiguities. We consider this model
supplemented by a Yukawa quasi-unification condition which allows an acceptable
b-quark mass. We find that the cosmological upper bound on the lightest
sparticle relic abundance is incompatible with the data on the branching ratio
of b-->s gamma, which is evaluated by including all the next-to-leading order
corrections. Thus, this scheme is not viable.Comment: 4 pages including 3 figures, Revte
Classical quasi-particle dynamics in trapped Bose condensates
The dynamics of quasi-particles in repulsive Bose condensates in a harmonic
trap is studied in the classical limit. In isotropic traps the classical motion
is integrable and separable in spherical coordinates. In anisotropic traps the
classical dynamics is found, in general, to be nonintegrable. For
quasi-particle energies E much smaller than thechemical potential, besides the
conserved quasi-particle energy, we identify two additional nearly conserved
phase-space functions. These render the dynamics inside the condensate
(collective dynamics) integrable asymptotically for E/chemical potential very
small. However, there coexists at the same energy a dynamics confined to the
surface of the condensate, which is governed by a classical Hartree-Fock
Hamiltonian. We find that also this dynamics becomes integrable for E/chemical
potential very small, because of the appearance of an adiabatic invariant. For
E/chemical potential of order 1 a large portion of the phase-space supports
chaotic motion, both, for the Bogoliubov Hamiltonian and its Hartree-Fock
approximant. To exemplify this we exhibit Poincar\'e surface of sections for
harmonic traps with the cylindrical symmetry and anisotropy found in TOP traps.
For E/chemical potential very large the dynamics is again governed by the
Hartree-Fock Hamiltonian. In the case with cylindrical symmetry it becomes
quasi-integrable because the remaining small chaotic components in phase space
are tightly confined by tori.Comment: 13 pages Latex, 6 eps.gz-figure
A Theory of Anisotropic Semiconductor of Heavy Fermions
It is demonstrated that a {\veck}-dependence of the hybridization matrix
element between - and conduction electrons can give rise to an anisotropic
hybridization gap of heavy fermions if the filling of electrons corresponds to
that of the band insulator. The most interesting case occurs when the
hybridization vanishes along some symmetry axis of the crystal reflecting a
particular symmetry of the crystal field. The results of a model calculation
are consistent with wide range of anomalous properties observed in CeNiSn and
its isostructural compounds, the anisotropic semiconductor of heavy fermions.
In particular, highly sensitive effect of impurity scattering on the residual
density of states for zero energy excitation and the anisotropic temperature
dependence of the resistivity are well explained. It is also discussed that a
weak semimetallic behavior arises through the weak \veck-dependence of the
-electron self-energy \Sigma_{f}(\veck,0).Comment: 21 pages, LaTeX (JPSJ style file) and 13 postscript figures, To
appear in J. Phys. Soc. Jp
Muon anomalous magnetic dipole moment in supersymmetric theories
We study the muon anomalous magnetic dipole moment in supersymmetric
theories. The impact of the recent Brookhaven E821 experimental measurement on
both model-independent and model-dependent supersymmetric parameter spaces is
discussed in detail. We find that values of tan\beta as low as 3 can be
obtained while remaining within the E821 one-sigma bound. This requires a light
smuon; however, we show that, somewhat surprisingly, no model-independent bound
can be placed on the mass of the lightest chargino for any tan\beta greater
than or equal to 3. We also show that the maximum contributions to the
anomalous magnetic moment are insensitive to CP-violating phases. We provide
analyses of the supersymmetric contribution to the muon anomalous magnetic
moment in dilaton-dominated supergravity models and gauge-mediated
supersymmetry-breaking models. Finally, we discuss how other phenomena, such as
, relic abundance of the lightest superpartner, and the Higgs
mass may be correlated with the anomalous magnetic moment, but do not
significantly impact the viability of a supersymmetric explanation, or the mass
limits obtainable on smuons and charginos.Comment: 28 page
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