Coexistence of long-range order for two observables at finite temperatures

We give a criterion for the simultaneous existence or non existence of two long-range orders for two observables, at finite temperatures, for quantum lattice many body systems. Our analysis extends previous results of G.-S. Tian limited to the ground state of similar models. The proof involves an inequality of Dyson-Lieb-Simon which connects the Duhamel two-point function to the usual correlation function. An application to the special case of the Holstein model is discussed.Comment: 12 pages, accepted for publication in J. of Phys.

Spider's Lane

Spider's Lane is a chapter from my novel-in-progress, Great Western Highway. In traditional novelistic terms, it deals with the novel's love story, as a young Sydney couple comes to grips with the decision to start a family in uncertain economic times, and explores themes of commitment and belonging in contemporary urban contexts. In more theoretical terms, it is an example of a literary figure I am developing, that of the affect sign. Drawing on Deleuze's conception of the representation of affect in Cinema, the chapter harnesses narrative (forward movement), setting, image and lyricism to create a tableau of affective sensation that is particular to novelistic representation. The central theme of Great Western Highway is the penetration of market forces into the social fabric of contemporary Western societies such as Australia. The novel also provides a model of structural innovation that revives experimentation within narrative form in contemporary Australian writing, which has traditionally been entrenched in realist modes. The research methodology of the project was highly interdisciplinary, involving engagements with Thatcherism; corporeal narratology (Punday); theories of the culture industry (Horkheimer & Adorno); the French nouveau roman (Simon); Modernism (Joyce, Celine); and aspects of Postmodernism that deal with popular culture and self-reflexivity in the literary and media fields (Jameson, Warhol). The novel was written with the assistance of three New Work grants from the Literature Board of the Australia Council, and highly commended in the NSW Writers' Fellowship 2000

Poor Karl Ove! Knausgaard’s selfie-as-novel

Here’s a telling snapshot of Karl Ove Knausgaard from early on in Some Rain Must Fall, the fifth instalment of his epic selfie-as-novel, My Struggle. It’s the late 1980s. Our young hero is 19 years old, readying himself to attend his first day at the Writing Academy, situated in the university town of Bergen

Words and World

One of the paradoxes of any artistic process is the transformation of the intensities of thought and sensation into the empirical fixities of form. For novelists, the sentence, paragraph and chapter are the standard textual forms that represent the richness of character, setting and event, and the insights into human nature they embody. In this paper I draw on approaches from literature, painting and poststructuralist philosophy to investigate the process by which words become world

Samuel Beckett, Claude Simon and the mise en abyme of paradoxical duplication

In his seminal study of novelistic mise en abyme structures, The Mirror in the Text, Lucien Dällenbach identifies a type he calls the mise en abyme of paradoxical duplication. Characterised by an extreme self-reflexivity, Dällenbach explores the operations of this literary trope in the later novels of the nouveau roman, particularly those of Claude Simon and Samuel Beckett. This article explores how Simon and Beckett employ this device with radically different results, Simon's forming part of a textual poetics that engages with the material and social, while Beckett's tends to a privileging of the self-reflexivity of language

The Novel, Sense-Making, and Mao

There was a in-joke floating around the University of Sydney when I was an arts student in the early 1980s that is telling of the times. It went something like this: Sydney has only one opera house, only one harbour bridge, but its university has two philosophy departments. One discipline, but two departments? Clearly, despite being friends of wisdom, these philosophers couldn’t agree. Somewhere in the hushed halls of the university’s sandstone towers, well before my time, some kind of schism had occurred, creating the Department of Traditional and Modern Philosophy, and the Department of General Philosophy. Looking at the course offerings, even my naïve undergraduate understanding could grasp the difference. Trad Mod was right-wing and conservative, and General was left-wing and progressive. In my first year, I decided to do subjects in both departments

Ground States and Flux Configurations of the Two-dimensional Falicov-Kimball Model

The Falicov-Kimball model is a lattice model of itinerant spinless fermions ("electrons") interacting by an on-site potential with classical particles ("ions"). We continue the investigations of the crystalline ground states that appear for various filling of electrons and ions, for large coupling. We investigate the model for square as well as triangular lattices. New ground states are found and the effects of a magnetic flux on the structure of the phase diagram is studied. The flux phase problem where one has to find the optimal flux configurations and the nuclei configurations is also solved in some cases. Finaly we consider a model where the fermions are replaced by hard-core bosons. This model also has crystalline ground states. Therefore their existence does not require the Pauli principle, but only the on-site hard-core constraint for the itinerant particles.Comment: 42 pages, uuencoded postscript file. Missing pages adde

Spectral flow and level spacing of edge states for quantum Hall hamiltonians

We consider a non relativistic particle on the surface of a semi-infinite cylinder of circumference $L$ submitted to a perpendicular magnetic field of strength $B$ and to the potential of impurities of maximal amplitude $w$. This model is of importance in the context of the integer quantum Hall effect. In the regime of strong magnetic field or weak disorder $B>>w$ it is known that there are chiral edge states, which are localised within a few magnetic lengths close to, and extended along the boundary of the cylinder, and whose energy levels lie in the gaps of the bulk system. These energy levels have a spectral flow, uniform in $L$, as a function of a magnetic flux which threads the cylinder along its axis. Through a detailed study of this spectral flow we prove that the spacing between two consecutive levels of edge states is bounded below by $2\pi\alpha L^{-1}$ with $\alpha>0$, independent of $L$, and of the configuration of impurities. This implies that the level repulsion of the chiral edge states is much stronger than that of extended states in the usual Anderson model and their statistics cannot obey one of the Gaussian ensembles. Our analysis uses the notion of relative index between two projections and indicates that the level repulsion is connected to topological aspects of quantum Hall systems.Comment: 22 pages, no figure

Geometric expansion of the log-partition function of the anisotropic Heisenberg model

We study the asymptotic expansion of the log-partition function of the anisotropic Heisenberg model in a bounded domain as this domain is dilated to infinity. Using the Ginibre's representation of the anisotropic Heisenberg model as a gas of interacting trajectories of a compound Poisson process we find all the non-decreasing terms of this expansion. They are given explicitly in terms of functional integrals. As the main technical tool we use the cluster expansion method.Comment: 38 page