Exact duality and dual Monte-Carlo simulation for the Bosonic Hubbard model

We derive the exact dual to the Bosonic Hubbard model. The dual variables take the form of conserved current loops (local and global). Previously this has been done only for the very soft core model at very high density. No such approximations are made here. In particular, the dual of the hard core model is shown to have a very simple form which is then used to construct an efficient Monte Carlo algorithm which is quite similar to the World Line algorithm but with some important differences. For example, with this algorithm we can measure easily the correlation function of the order parameter (Green function), a quantity which is extremely difficult to measure with the standard World Line algorithm. We demonstrate the algorithm for the one and two dimensional hardcore Bosonic Hubbard models. We present new results especially for the Green function and zero mode filling fraction in the two dimensional hardcore model.Comment: 14 pages, 15 figures include

Algebraic and Computer-based Methods in the Undirected Degree/diameter Problem - a Brief Survey

This paper discusses the most popular algebraic techniques and computational methods that have been used to construct large graphs with given degree and diameter

Electronic Correlations in CoO2, the Parent Compound of Triangular Cobaltates

A 59Co NMR study of CoO2, the x=0 end member of AxCoO2 (A = Na, Li...) cobaltates, reveals a metallic ground state, though with clear signs of strong electron correlations: low-energy spin fluctuations develop at wave vectors q different from 0 and a crossover to a Fermi-liquid regime occurs below a characteristic temperature T*~7 K. Despite some uncertainty over the exact cobalt oxidation state n this material, the results show that electronic correlations are revealed as x is reduced below 0.3. The data are consistent with NaxCoO2 being close to the Mott transition in the x -> 0 limit.Comment: 4 pages, submitte

I Did it For Me: Negotiating identity and agency

Scholars have debated the feminist critique of female beauty practices for years with the fundamental disagreement revolving around the notion of “agency.” This study used textual analysis to explore how the concept of “agency” has been employed in cosmetic surgery ads placed in large city magazines.   Three themes emerged: realize your potential, pleasing yourself, and control your destiny.  This research expands our understanding of how physicians are repositioning cosmetic surgery to women through discourses that empower, appeal to their sense of self, and play upon feminist sensibilities that privilege individual choice. This research also contributes to the literature surrounding the ongoing debate of agency by examining how it plays out in another form of text previously unexamined (physician advertising) and how it touches upon a new player in the health beauty system (physicians) rather than prior studies, which focus on idealized images in the media