Erdős Number
While I’m not strictly speaking a mathematician, I always wondered what my Erdős Number would be. The Erdős calculated of an author is calculated the following way: Paul Erdős has number 0, people who have coauthored a paper with him have a number 1, people who co-write papers with people with a number of 1 have a number of 2, etc.
So I took advantage of this snowy Sunday to search for a path between Paul Erdős and myself. If you have published mathematical papers, you just need to search for yourself on the collaboration distance tool. But as I have not published any mathematical paper, I had to try out the various people I cowrote papers with, and see what would come out. I then had to look for the people they co-wrote with to find a better path. I found the following four step path:
- Paul Erdős → Stanley M. Selkow: Random graph isomorphism.
- Stanley M. Selkow → Giovanni Coray: Order independence in local clustering algorithms.
- Giovanni Coray → André Schiper: Une structure de contrôle à deux niveaux pour la programmation heuristique parallèle.
- André Schiper → Matthias Wiesmann: Beyond 1-safety and 2-safety for replicated databases: Group-safety
The first five step path I had found was the following:
- Paul Erdős → Shmuel Zaks: Minimum-diameter cyclic arrangements in mapping data-flow graphs onto VLSI arrays
- Shmuel Zaks → Gerard Tel: Optimal synchronization of ABD networks
- Gerard Tel → Bernadette Charron-Bost: Synchronous, asynchronous, and causally ordered communication
- Bernadette Charron-Bost → André Schiper: Uniform consensus is harder than consensus
- André Schiper → Matthias Wiesmann: Beyond 1-safety and 2-safety for replicated databases: Group-safety
But there is at least another 5 step possibility:
- Paul Erdős → Ronald L. Graham: On sums of Fibonnaci numbers.
- Ronald L. Graham → John L. Bruno: Computer and job-shop scheduling theory.
- John L. Bruno → Divyakant Agrawal: Relative serializability: an approach for relaxing the atomicity of transactions.
- Divyakant Agrawal → Gustavo Alonso: Advanced Transaction Models in Workflow Contexts.
- Gustavo Alonso → Matthias Wiesmann: Understanding replication in databases and distributed systems.
I also found two different path of length 6:
- Paul Erdős → Fan Chung: On the product of the point and line covering numbers of a graph
- Fan Chung → Patrick Solé: Patrick Multidiameters and multiplicities
- Patrick Solé → Peter J. Olver: Generalized transvectants and Siegel modular forms
- Peter J. Olver → Metin Arık: Multi-Hamiltonian structure of the Born-Infeld equation
- Metin Arık → Gökhan Ünel: q-oscillators, the q-epsilon tensor and quantum groups
- Gökhan Ünel → Matthias Wiesmann: Deployment and use of the ATLAS DAQ in the combined test beam
- Paul Erdős → Alexander Rosa: Decompositions of complete graphs into factors with diameter two.
- Alexander Rosa → Jean-Claude Bermond: Decomposition of complete graphs into isomorphic subgraphs with five vertices.
- Jean-Claude Bermond → Michel Raynal: General and efficient decentralized consensus protocols.
- Michel Raynal → Maria Gradinariu: Stabilizing mobile philosophers.
- Maria Gradinariu → Xavier Défago: Fault-tolerant and self-stabilizing mobile robots gathering – feasibility study.
- Xavier Défago → Matthias Wiesmann: Anonymous stabilizing leader election using a network sequencer.

It seems That’s just a specialization of the six degree of separation concept / theory:
http://en.wikipedia.org/wiki/Six_degrees_of_separation
It’s the Kevin Bacon Index for mathematicians.
What about fractional erdoes number? Like dividing by the number of disjoint paths to Erdoes? My frac EN is one i think..