31,498 research outputs found
From the social learning theory to a social learning algorithm for global optimization
Traditionally, the Evolutionary Computation (EC) paradigm is inspired by Darwinian evolution or the swarm intelligence of animals. Bandura's Social Learning Theory pointed out that the social learning behavior of humans indicates a high level of intelligence in nature. We found that such intelligence of human society can be implemented by numerical computing and be utilized in computational algorithms for solving optimization problems. In this paper, we design a novel and generic optimization approach that mimics the social learning process of humans. Emulating the observational learning and reinforcement behaviors, a virtual society deployed in the algorithm seeks the strongest behavioral patterns with the best outcome. This corresponds to searching for the best solution in solving optimization problems. Experimental studies in this paper showed the appealing search behavior of this human intelligence-inspired approach, which can reach the global optimum even in ill conditions. The effectiveness and high efficiency of the proposed algorithm has further been verified by comparing to some representative EC algorithms and variants on a set of benchmarks
Determinations of form factors for semileptonic decays and leptoquark constraints
By analyzing all existing measurements for ( ) decays, we find that the determinations of both the vector
form factor and scalar form factor for semileptonic
decays from these measurements are feasible. By taking the
parameterization of the one order series expansion of the and
, is determined to be , and the
shape parameters of and are
and , respectively. Combining with the average
of and lattice calculaltion, the is extracted
to be where the first error is experimental and the
second theoretical. Alternatively, the is extracted to be
by taking the as the value from the global
fit with the unitarity constraint of the CKM matrix. Moreover, using the
obtained form factors by lattice QCD, we re-analyze these
measurements in the context of new physics. Constraints on scalar leptoquarks
are obtained for different final states of semileptonic
decays
Scale Invariance vs. Conformal Invariance: Holographic Two-Point Functions in Horndeski Gravity
We consider Einstein-Horndeski gravity with a negative bare constant as a
holographic model to investigate whether a scale invariant quantum field theory
can exist without the full conformal invariance. Einstein-Horndeski gravity can
admit two different AdS vacua. One is conformal, and the holographic two-point
functions of the boundary energy-momentum tensor are the same as the ones
obtained in Einstein gravity. The other AdS vacuum, which arises at some
critical point of the coupling constants, preserves the scale invariance but
not the special conformal invariance due to the logarithmic radial dependence
of the Horndeski scalar. In addition to the transverse and traceless graviton
modes, the theory admits an additional trace/scalar mode in the scale invariant
vacuum. We obtain the two-point functions of the corresponding boundary
operators. We find that the trace/scalar mode gives rise to an non-vanishing
two-point function, which distinguishes the scale invariant theory from the
conformal theory. The two-point function vanishes in , where the full
conformal symmetry is restored. Our results indicate the strongly coupled scale
invariant unitary quantum field theory may exist in without the full
conformal symmetry. The operator that is dual to the bulk trace/scalar mode
however violates the dominant energy condition.Comment: Latex, 28 pages, comments and references adde
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