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Enterprise Risk Management: Review, Critique, and Research Directions
© 2014 Elsevier Ltd. Many regulators, rating agencies, executives and academics have advocated a new approach to risk management: Enterprise Risk Management (ERM). ERM proposes the integrated management of all the risks an organization faces, which inherently requires alignment of risk management with corporate governance and strategy. Academic research on ERM is still in its infancy, with articles largely in accounting and finance journals but rarely in management journals. We argue that ERM offers an important new research domain for management scholars. A critical review of ERM research allows us to identify limitations and gaps that management scholars are best equipped to address. This paper not only identifies how management scholars can contribute to ERM research, but also points out why ERM research (and practice) needs management research for its development
Discriminating quantum-optical beam-splitter channels with number-diagonal signal states: Applications to quantum reading and target detection
We consider the problem of distinguishing, with minimum probability of error,
two optical beam-splitter channels with unequal complex-valued reflectivities
using general quantum probe states entangled over M signal and M' idler mode
pairs of which the signal modes are bounced off the beam splitter while the
idler modes are retained losslessly. We obtain a lower bound on the output
state fidelity valid for any pure input state. We define number-diagonal signal
(NDS) states to be input states whose density operator in the signal modes is
diagonal in the multimode number basis. For such input states, we derive series
formulas for the optimal error probability, the output state fidelity, and the
Chernoff-type upper bounds on the error probability. For the special cases of
quantum reading of a classical digital memory and target detection (for which
the reflectivities are real valued), we show that for a given input signal
photon probability distribution, the fidelity is minimized by the NDS states
with that distribution and that for a given average total signal energy N_s,
the fidelity is minimized by any multimode Fock state with N_s total signal
photons. For reading of an ideal memory, it is shown that Fock state inputs
minimize the Chernoff bound. For target detection under high-loss conditions, a
no-go result showing the lack of appreciable quantum advantage over coherent
state transmitters is derived. A comparison of the error probability
performance for quantum reading of number state and two-mode squeezed vacuum
state (or EPR state) transmitters relative to coherent state transmitters is
presented for various values of the reflectances. While the nonclassical states
in general perform better than the coherent state, the quantitative performance
gains differ depending on the values of the reflectances.Comment: 12 pages, 7 figures. This closely approximates the published version.
The major change from v2 is that Section IV has been re-organized, with a
no-go result for target detection under high loss conditions highlighted. The
last sentence of the abstract has been deleted to conform to the arXiv word
limit. Please see the PDF for the full abstrac
Circular dichroism of magneto-phonon resonance in doped graphene
Polarization resolved, Raman scattering response due to E phonon in
monolayer graphene has been investigated in magnetic fields up to 29 T. The
hybridization of the E phonon with only the fundamental inter Landau
level excitation (involving the n=0 Landau level) is observed and only in one
of the two configurations of the circularly crossed polarized excitation and
scattered light. This polarization anisotropy of the magneto-phonon resonance
is shown to be inherent to relatively strongly doped graphene samples, with
carrier concentration typical for graphene deposited on SiO
Charged solutions in 5d Chern-Simons supergravity
A family of solutions with mass and electric charge of five-dimensional
Chern-Simons supergravity is displayed. The action contains an extra term that
changes the value of the cosmological constant, as considered by Horava. It is
shown that the solutions approach asymptotically the Reissner-Nordstrom
spacetime. The role of the torsion tensor in providing charged solutions is
stressed.Comment: Minor changes. To appear in PRD. 8 pages, RevTeX 4, two colum
Gluon mass generation without seagull divergences
Dynamical gluon mass generation has been traditionally plagued with seagull
divergences, and all regularization procedures proposed over the years yield
finite but scheme-dependent gluon masses. In this work we show how such
divergences can be eliminated completely by virtue of a characteristic
identity, valid in dimensional regularization. The ability to trigger the
aforementioned identity hinges crucially on the particular Ansatz employed for
the three-gluon vertex entering into the Schwinger-Dyson equation governing the
gluon propagator. The use of the appropriate three-gluon vertex brings about an
additional advantage: one obtains two separate (but coupled) integral
equations, one for the effective charge and one for the gluon mass. This system
of integral equations has a unique solution, which unambiguously determines
these two quantities. Most notably, the effective charge freezes in the
infrared, and the gluon mass displays power-law running in the ultraviolet, in
agreement with earlier considerations.Comment: 37 pages, 9 figures; minor typos corrected and a few brief
explanatory remarks adde
UV divergence-free QFT on noncommutative plane
We formulate Noncommutative Qauntum Field Theory in terms of fields defined
as mean value over coherent states of the noncommutative plane. No *-product is
needed in this formulation and noncommutativity is carried by a modified
Fourier transform of fields. As a result the theory is UV finite and the cutoff
is provided by the noncommutative parameter theta.Comment: 6 pages, Latex, no figures. Accepted for publication in J.Phys.A. New
references adde
Phase separation and the effect of quenched disorder in
The nature of phase separation in has been probed by
linear as well as nonlinear magnetic susceptibilities and resistivity
measurements across the 2nd order paramagnetic to ferromagnetic transition
() and 1st order ferromagnetic to antiferromagnetic transition (). We
found that the ferromagnetic (metallic) clusters, which form with the onset of
long-range order in the system at , continuously decrease their size with
the decrease in temperature and coexist with non-ferromagnetic (insulating)
clusters. These non-ferromagnetic clusters are identified to be
antiferromagnetic. Significantly, it is shown that they do not arise because of
the superheating effect of the lower temperature 1st order transition. Thus
reveals unique phase coexistence in a manganite around half-doping encompassing
two long-range order transitions. Both the ferromagnetic and antiferromagnetic
clusters form at and persist much below . Substitution of quenched
disorder (Ga) at Mn-site promotes antiferromagnetism at the cost of
ferromagnetism without adding any magnetic interaction or introducing any
significant lattice distortion. Moreover, increase in disorder decreases the
ferromagnetic cluster size and with 7.5% Ga substitution clusters size reduces
to the single domain limit. Yet, all the samples show significant short-range
ferromagnetic interaction much above . Resistivity measurements also
reveal the novel phase coexistence identified from the magnetic measurements.
It is significant that, increase in disorder up to 7.5% increases the
resistivity of the low temperature antiferromagnetic phase by about four
orders
Selective substitution in orbital domains of a low doped manganite : an investigation from Griffiths phenomenon and modification of glassy features
An effort is made to study the contrast in magnetic behavior resulting from
minimal disorder introduced by substitution of 2.5% Ga or Al in Mn-site of
LaSrMnO. It is considered that Ga or Al selectively
creates disorder within the orbital domains or on its walls, causing
enhancement of Griffiths phase (GP) singularity for the former and
disappearance of it in the later case. It is shown that Ga replaces Mn
which is considered to be concentrated within the domains, whereas Al replaces
Mn which is segregated on the hole-rich walls, without causing any
significant effect on structure or ferromagnetic transition temperatures. Thus,
it is presumed that the effect of disorder created by Ga extend across the bulk
of the domain having correlation over similar length-scale resulting in
enhancement of GP phenomenon. On the contrary, effect of disorder created by Al
remains restricted to the walls resulting in the modification of the dynamics
arising from the domain walls and suppresses the GP. Moreover contrasting
features are observed in the low temperature region of the compounds; a
re-entrant spin glass like behavior is observed in the Ga doped sample, while
the observed characteristics for the Al doped sample is ascribed only to
modified domain wall dynamics with the absence of any glassy phase. Distinctive
features in third order susceptibility measurements reveals that the magnetic
ground state of the entire series comprises of orbital domain states. These
observations bring out the role of the nature of disorder on GP phenomenon and
also reconfirms the character of self-organization in low-doped manganites
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