Drift of a polymer chain in disordered media

We consider the drift of a polymer chain in a disordered medium, which is caused by a constant force applied to the one end of the polymer, under neglecting the thermal fluctuations. In the lowest order of the perturbation theory we have computed the transversal fluctuations of the centre of mass of the polymer, the transversal and the longitudinal size of the polymer, and the average velocity of the polymer. The corrections to the quantities under consideration, which are due to the interplay between the motion and the quenched forces, are controlled by the driving force and the degree of polymerization. The transversal fluctuations of the Brownian particle and of the centre of mass of the polymer are obtained to be diffusive. The transversal fluctuations studied in the present Letter may also be of relevance for the related problem of the drift of a directed polymer in disordered media and its applications.Comment: 11 pages, RevTex, Accepted for publication in Europhysics Letter

Statistical regularities in the rank-citation profile of scientists

Recent science of science research shows that scientific impact measures for journals and individual articles have quantifiable regularities across both time and discipline. However, little is known about the scientific impact distribution at the scale of an individual scientist. We analyze the aggregate production and impact using the rank-citation profile ci(r) of 200 distinguished professors and 100 assistant professors. For the entire range of paper rank r, we fit each ci(r) to a common distribution function. Since two scientists with equivalent Hirsch h-index can have significantly different ci(r) profiles, our results demonstrate the utility of the βi scaling parameter in conjunction with hi for quantifying individual publication impact. We show that the total number of citations Ci tallied from a scientist's Ni papers scales as . Such statistical regularities in the input-output patterns of scientists can be used as benchmarks for theoretical models of career progress

Periodic orbits in a coupled map lattice model, in 'Cellular Automata and Modeling of Complex Physical Systems', (Les Houches, April 1989), Springer Proceedings in Physics, Vol. 46, P. Manneville, N. Boccara and G. Y. Vichniac eds., Springer-Verlag Berlin, Heidelberg,

We investigate the structure of the set of periodic orbits for lattices of coupled piece-wise linear maps exhibiting chaotic behavior, characterizing the bifurcation set when an external parameter is varied

Do social sciences and humanities behave like life and hard sciences?

The quantitative evaluation of Social Science and Humanities (SSH) and the investigation of the existing similarities between SSH and Life and Hard Sciences (LHS) represent the forefront of scientometrics research. We analyse the scientific production of the universe of Italian academic scholars , over a 10-year period across 2002–2012, from a national database built by the Italian National Agency for the Evaluation of Universities and Research Institutes. We demonstrate that all Italian scholars of SSH and LHS are equals, as far as their publishing habits. They share the same general law, which is a lognormal. At the same time, however, they are different, because we measured their scientific production with different indicators required by the Italian law; we eliminated the “silent” scholars and obtained different scaling values—proxy of their productivity rates. Our findings may be useful to further develop indirect quali–quantitative comparative analysis across heterogeneous disciplines and, more broadly, to investigate on the generative mechanisms behind the observed empirical regularities. © 2017, Akadémiai Kiadó, Budapest, Hungary