Browsing by Publisher "IOP Publishing Ltd"
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Collective enhancement of nuclear state densities by the shell model Monte Carlo approach
Authors:
Publisher and Date:(IOP Publishing Ltd, 2015)The shell model Monte Carlo (SMMC) approach allows for the microscopic calculation of statistical and collective properties of heavy nuclei using the framework of the configurationinteraction shell model in very large model spaces. We present recent applications of the SMMC method to the calculation of state densities and their collective enhancement factors in rareearth nuclei.

'Level grading' a new graded algebra structure on differential polynomials: application to the classification of scalar evolution equations
Authors:
Publisher and Date:(IOP Publishing Ltd, 2013)We define a new grading which we call the 'level grading' on the algebra of polynomials generated by the derivatives u(k+i) over the ring K(k) of Cinfinity functions of x t u u(1) ... u(k) where . This grading has the property that the total derivative and the integration by parts with respect to x are filtered algebra maps. In addition if u satisfies the evolution equation u(j) = F[u] where F is a polynomial of order m = k + p and of level p then the total derivative with respect to t Dt is ...

A mathematical characterization of the gel point in solgel transition
Authors:
Publisher and Date:(IOP Publishing Ltd, 2015)We model the solgel transition in terms of SusceptibleInfectedRemoved (SIR) and SusceptibleExposedInfectedRemoved (SEIR) models and compare with experimental results. We show, numerically, that the "gel point" described as the onset of the gelation phenomena and measured experimentally, corresponds to an accumulation point of the extreme values of the derivatives of the gelation curve. We define the "critical point of a sigmoidal curve" as the limit of the points where the derivatives reach ...

On the classification of scalar evolution equations with nonconstant separant
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Publisher and Date:(IOP Publishing Ltd, 2017)The ` separant' of the evolution equation u(t) = F where F is some differentiable function of the derivatives of u up to order m is the partial derivative partial derivative F/partial derivative u(m) where um u(m) = partial derivative(m)u/partial derivative x(m). As an integrability test we use the formal symmetry method of MikhailovShabatSokolov which is based on the existence of a recursion operator as a formal series. The solvability of its coefficients in the class of local functions gives ...

On the uniqueness of the octonionic instanton solution on conformally flat 8manifolds
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Publisher and Date:(IOP Publishing Ltd, 2016)Let M be an 8manifold and E be an SO(8) bundle on M. In a previous paper [F. Ozdemir and A.H. Bilge, "Selfduality in dimensions 2n > 4: equivalence of various definitions and the derivation of the octonionic instanton solution", ARI (1999) 51:247253], we have shown that if the second Pontrjagin number p(2) of the bundle E is minimal, then the components of the curvature 2form matrix F with respect to a local orthonormal frame are Fij = c(ij)omega(ij), where c(ij)'s are certain functions and ...

Recent Advances in the Application of the Shell Model Monte Carlo Approach to Nuclei
Authors:
Publisher and Date:(IOP Publishing Ltd, 2015)The shell model Monte Carlo (SMMC) method is a powerful technique for calculating the statistical and collective properties of nuclei in the presence of correlations in model spaces that are many orders of magnitude larger than those that can be treated by conventional diagonalization methods. We review recent advances in the development and application of SMMC to midmass and heavy nuclei.

Recent developments in the shell model Monte Carlo approach to nuclei
Authors:
Publisher and Date:(IOP Publishing Ltd, 2012)The shell model Monte Carlo (SMMC) approach provides a powerful method for the microscopic calculation of statistical and collective nuclear properties in model spaces that are many orders of magnitude larger than those that can be treated by conventional methods. We discuss recent applications of the method to describe the emergence of collectivity in the framework of the configurationinteraction shell model and the crossover from vibrational to rotational collectivity in families of rareearth ...

Selfduality in higher dimensions
Authors:
Publisher and Date:(IOP Publishing Ltd, 2017)Let w be a 2form on a 2n dimensional manifold. In previous work, we called w "strong selfdual, if the eigenvalues of its matrix with respect to an orthonormal frame are equal in absolute value. In a series of papers, we showed that strong selfduality agrees with previous definitions; in particular if w is strong selfdual, then, in 2n dimensions, w(n) is proportional to its Hodge dual w and in 4n dimensions, w(n) is Hodge selfdual. We also obtained a local expression of the Bonan 4form on 8 ...