Dear Colleagues,
we would like to invite you to the following Probability seminar that 
will take place at the Department of Mathematics of Padova, on January 31.
________________________________________________________

Speaker:  Alessandra Cipriani (TU Delft)

Title: Dynamical fitness models: evidence of universality classes for preferential attachment

 31 JANUARY (Friday), 11:30; ROOM 1BC45, Dipartimento di Matematica 
“Tullio Levi-Civita”, Via Trieste 63, Padova

Abstract: In this talk we study different variations of a particular class 
of random graphs called preferential attachment models with fitness. 
These are dynamic graphs in which, at every time step, a new node attaches 
itself to an older one with probability proportional to the degree and a random
 factor associated to the node, called the fitness.
Motivated by learning mechanisms of real-life networks, we assume the fitness 
to be a Moving Average process MA(q) with positive increments. 
We study different properties of such models, for example the degree distribution,
 the attachment probability and the phenomenon of Bose-Einstein condensation.
 Finally we provide evidence that, tuning the parameters of the fitness process,
 we fall into two universality classes represented by the well-known 
Albert-Barabàsi model and Bianconi-Barabàsi model. 
This implies the robustness of heavy tails in the degree distribution 
under random perturbations of the attachment rule.



All of you are very welcome.

Best regards,
Alessandra Bianchi 


--
Alessandra Bianchi
Dip. di Matematica
Università di Padova

Via Trieste, 63 - 35121 Padova, Italy

phone:    +39 049 827 14 06
fax:        +39 049 827 14 28
e-mail:    bianchi@math.unipd.it
http://www.math.unipd.it/~bianchi/