8,651 research outputs found
WEAK MEASUREMENT THEORY AND MODIFIED COGNITIVE COMPLEXITY MEASURE
Measurement is one of the problems in the area of software engineering. Since traditional measurement
theory has a major problem in defining empirical observations on software entities in terms of their
measured quantities, Morasca has tried to solve this problem by proposing Weak Measurement theory. In
this paper, we tried to evaluate the applicability of weak measurement theory by applying it on a newly
proposed Modified Cognitive Complexity Measure (MCCM). We also investigated the applicability of
Weak Extensive Structure for deciding on the type of scale for MCCM. It is observed that the MCCM is on
weak ratio scale
A Variational Approach to Bound States in Quantum Field Theory
We consider here in a toy model an approach to bound state problem in a
nonperturbative manner using equal time algebra for the interacting field
operators. Potential is replaced by offshell bosonic quanta inside the bound
state of nonrelativistic particles. The bosonic dressing is determined through
energy minimisation, and mass renormalisation is carried out in a
nonperturbative manner. Since the interaction is through a scalar field, it
does not include spin effects. The model however nicely incorporates an
intuitive picture of hadronic bound states in which the gluon fields dress the
quarks providing the binding between them and also simulate the gluonic content
of hadrons in deep inelastic collisions.Comment: latex, revtex, 22 page
An N=1 Triality by Spectrum Matching
On promoting the type IIA side of the N=1 Heterotic/type IIA dual pairs of
[1] to M-theory on a `barely G_2 Manifold' of [2], by spectrum-matching we show
a possible triality between Heterotic on a self-mirror Calabi-Yau, M-theory on
the above `barely G_2-Manifold' constructed from the Calabi-Yau on the type IIA
side and -theory on an elliptically fibered Calabi-Yau 4-fold fibered over a
trivially rationally ruled CP^1 x E base, E being the Enriques surface. We
raise an apparent puzzle on the F-theory side, namely, the Hodge data of the
4-fold derived can not be obtained by a naive freely acting orbifold of
CY_3(3,243) x T^2 as one might have guessed on the basis of arguments related
to dualities involving string, M and (definition of) F theories. There are some
interesting properties of the antiholomorphic involution used in \cite{VW} for
constructing the type IIA orientifold and by us in constructing the 'barely G_2
manifold', that we also study.Comment: 14 pages, LaTex; v3: journal versio
Modulational instability of ion-acoustic wave packets in quantum pair-ion plasmas
Amplitude modulation of quantum ion-acoustic waves (QIAWs) in a quantum
electron-pair-ion plasma is studied. It is shown that the quantum coupling
parameter (being the ratio of the plasmonic energy density to the Fermi
energy) is ultimate responsible for the modulational stability of QIAW packets,
without which the wave becomes modulational unstable. New regimes for the
modulational stability (MS) and instability (MI) are obtained in terms of
and the positive to negative ion density ratio . The growth rate of MI
is obtained, the maximum value of which increases with and decreases
with . The results could be important for understanding the origin of
modulated QIAW packets in the environments of dense astrophysical objects,
laboratory negative ion plasmas as well as for the next generation laser solid
density plasma experiments.Comment: 4 pages, 2 figures (to appear in Astrophysics and Space Science
Flow Equations for Uplifting Half-Flat to Spin(7) Manifolds
In this short supplement to [1], we discuss the uplift of half-flat six-folds
to Spin(7) eight-folds by fibration of the former over a product of two
intervals. We show that the same can be done in two ways - one, such that the
required Spin(7) eight-fold is a double G_2 seven-fold fibration over an
interval, the G_2 seven-fold itself being the half-flat six-fold fibered over
the other interval, and second, by simply considering the fibration of the
half-flat six-fold over a product of two intervals. The flow equations one gets
are an obvious generalization of the Hitchin's flow equations (to obtain
seven-folds of G_2 holonomy from half-flat six-folds [2]). We explicitly show
the uplift of the Iwasawa using both methods, thereby proposing the form of the
new Spin(7) metrics. We give a plausibility argument ruling out the uplift of
the Iwasawa manifold to a Spin(7) eight fold at the "edge", using the second
method. For eight-folds of the type , being a
seven-fold of SU(3) structure, we motivate the possibility of including
elliptic functions into the "shape deformation" functions of seven-folds of
SU(3) structure of [1] via some connections between elliptic functions, the
Heisenberg group, theta functions, the already known -brane metric [3] and
hyper-K\"{a}hler metrics obtained in twistor spaces by deformations of
Atiyah-Hitchin manifolds by a Legendre transform in [4].Comment: 12 pages, LaTeX; v3: (JMP) journal version which includes clarifying
remarks related to connection between Spin(7)-folds and SU(3)structur
Gluon Condensates, Chiral Symmetry Breaking and Pion Wave Function
We consider here chiral symmetry breaking in quantum chromodynamics arising
from gluon condensates in vacuum. Through coherent states of gluons simulating
a mean field type of approximation, we show that the off-shell gluon
condensates of vacuum generate a mass-like contribution for the quarks, giving
rise to chiral symmetry breaking. We next note that spontaneous breaking of
global chiral symmetry links the four component quark field operator to the
pion wave function. This in turn yields many hadronic properties in the light
quark sector in agreement with experiments, leading to the conclusion that low
energy hadron properties are primarily driven by the vacuum structure of
quantum chromodynamics.Comment: 25 pages, IP/BBSR/92-76, revte
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