arXiv subjects

G. Mukherjee

Publications and source records attributed to G. Mukherjee.

59 records · Page 4Linked to original sources

arXiv2005

Phase transition in a directed traffic flow network

The generic feature of traffic in a network of flowing electronic data packets is a phase transition from a stationary free-flow phase to a continuously growing congested non-stationary phase. In the most simple network of directed oriented square lattice we have been able to observe all crucial features of such flow systems having non-trivial critical behavior near the critical point of transition. The network here is in the shape of a square lattice and data packets are randomly posted with a rate $ρ$ at one side of the lattice. Each packet executes a directed diffusive motion towards the opposite boundary where it is delivered. Packets accumulated at a particular node form a queue and a maximum of $m$ such packets randomly jump out of this node at every time step to its neighbors on a first-in-first-out (FIFO) basis. The phase transition occurs at $ρ_c=m$. The distribution of travel times through the system is found to have a log-normal behavior and the power-spectrum of the load time-series shows $1/f$ like noise similar to the scenario of Internet traffic.

cond-mat.stat-mech↗

arXiv2004

Influence of nuclear structure on sub-barrier hindrance in Ni+Ni fusion

Fusion-evaporation cross sections for $^{64}$Ni+$^{64}$Ni have been measured down to the 10 nb level. For fusion between two open-shell nuclei, this is the first observation of a maximum in the $S$-factor, which signals a strong sub-barrier hindrance. A comparison with the $^{58}$Ni+$^{58}$Ni, $^{58}$Ni+$^{60}$Ni, and $^{58}$Ni+$^{64}$Ni systems indicates a strong dependence of the energy where the hindrance occurs on the stiffness of the interacting nuclei.

nucl-ex↗

arXiv2003

Scale-free network on a vertical plane

A scale-free network is grown in the Euclidean space with a global directional bias. On a vertical plane, nodes are introduced at unit rate at randomly selected points and a node is allowed to be connected only to the subset of nodes which are below it using the attachment probability: $π_i(t) \sim k_i(t)\ell^α$. Our numerical results indicate that the directed scale-free network for $α=0$ belongs to a different universality class compared to the isotropic scale-free network. For $α< α_c$ the degree distribution is stretched exponential in general which takes a pure exponential form in the limit of $α\to -\infty$. The link length distribution is calculated analytically for all values of $α$.

cond-mat.stat-mech↗

arXiv2002

Small-world properties of the Indian Railway network

Structural properties of the Indian Railway network is studied in the light of recent investigations of the scaling properties of different complex networks. Stations are considered as `nodes' and an arbitrary pair of stations is said to be connected by a `link' when at least one train stops at both stations. Rigorous analysis of the existing data shows that the Indian Railway network displays small-world properties. We define and estimate several other quantities associated with this network.

cond-mat.soft↗

arXiv2002

Quasistatic Scale-free Networks

A network is formed using the $N$ sites of an one-dimensional lattice in the shape of a ring as nodes and each node with the initial degree $k_{in}=2$. $N$ links are then introduced to this network, each link starts from a distinct node, the other end being connected to any other node with degree $k$ randomly selected with an attachment probability proportional to $k^α$. Tuning the control parameter $α$ we observe a transition where the average degree of the largest node $ $ changes its variation from $N^0$ to $N$ at a specific transition point of $α_c$. The network is scale-free i.e., the nodal degree distribution has a power law decay for $α\ge α_c$.

cond-mat.stat-mech↗