s . so c - ph ] 1 9 Ju l 2 00 6 Adapting to heterogeneous comfort levels

s . so c - ph ] 1 9 Ju l 2 00 7 Community Structure in the United States House of Representatives

We investigate the networks of committee and subcommittee assignments in the United States House of Representatives from the 101st–108th Congresses, with the committees connected by “interlocks” or common membership. We examine the community structure in these networks using several methods, revealing strong links between certain committees as well as an intrinsic hierarchical structure in the ...

ar X iv : 0 90 6 . 12 19 v 2 [ ph ys ic s . at om - p h ] 2 5 Ju l 2 00 9 Spin - 1 / 2 Optical Lattice Clock

We experimentally investigate an optical clock based on Yb (I = 1/2) atoms confined in an optical lattice. We have evaluated all known frequency shifts to the clock transition, including a densitydependent collision shift, with a fractional uncertainty of 3.4 × 10, limited principally by uncertainty in the blackbody radiation Stark shift. We measured the absolute clock transition frequency rela...

ar X iv : 0 90 7 . 20 23 v 1 [ m at h - ph ] 1 2 Ju l 2 00 9 Menelaus relation and Fay ’ s trisecant formula are associativity equations

It is shown that the celebrated Menelaus relation and Fay's trisecant formula similar to the WDVV equation are associativity conditions for structure constants of certain three-dimensional algebra.

ar X iv : m at h - ph / 0 60 70 40 v 1 2 0 Ju l 2 00 6 Invariant Form of BK - factorization and its Applications

s . so c - ph ] 1 1 Ju l 2 00 6 Virtual volatility

We introduce the concept of virtual volatility. This simple but new measure shows how to quantify the uncertainty in the forecast of the drift component of a random walk. The virtual volatility also is a useful tool in understanding the stochastic process for a given portfolio. In particular, and as an example, we were able to identify mean reversion effect in our portfolio. Finally, we briefly...