The group of causal automorphisms

The group of causal automorphisms on Minkowski space-time is given and its structure is analyzed

Particle Correlation Results from the ALICE Experiment at LHC

Measurements of two-particle correlations of inclusive and identified charged particles performed with the ALICE detector in Pb--Pb collisions at $\sqrt{s_{NN}} = 2.76 TeV$ are presented. The near-side jet shape is analyzed in the low $p_{\rm T}$ regions ($1<$p_{\rm T}$<8GeV/c$). While the RMS of the peak in $\Delta\varphi$-direction is independent of centrality within uncertainties, we find significant broadening in $\Delta\eta$-direction from peripheral to central collisions. The near-side $p/\pi$ ratio of particles associated to a trigger particle from jet fragmentation in the central Pb--Pb collisions is consistent with vacuum fragmentation in the measured momentum region ($1.5<$p_{\rm T}<4.5GeV\c).Comment: 8 pages, 6 figures, proceeding for Physics at LHC 2012, vancouver, Canad

Disassortativity of random critical branching trees

Random critical branching trees (CBTs) are generated by the multiplicative branching process, where the branching number is determined stochastically, independent of the degree of their ancestor. Here we show analytically that despite this stochastic independence, there exists the degree-degree correlation (DDC) in the CBT and it is disassortative. Moreover, the skeletons of fractal networks, the maximum spanning trees formed by the edge betweenness centrality, behave similarly to the CBT in the DDC. This analytic solution and observation support the argument that the fractal scaling in complex networks originates from the disassortativity in the DDC.Comment: 3 pages, 2 figure