17,180 research outputs found
Untwisting information from Heegaard Floer homology
The unknotting number of a knot is the minimum number of crossings one must
change to turn that knot into the unknot. We work with a generalization of
unknotting number due to Mathieu-Domergue, which we call the untwisting number.
The p-untwisting number is the minimum number (over all diagrams of a knot) of
full twists on at most 2p strands of a knot, with half of the strands oriented
in each direction, necessary to transform that knot into the unknot. In
previous work, we showed that the unknotting and untwisting numbers can be
arbitrarily different. In this paper, we show that a common route for
obstructing low unknotting number, the Montesinos trick, does not generalize to
the untwisting number. However, we use a different approach to get conditions
on the Heegaard Floer correction terms of the branched double cover of a knot
with untwisting number one. This allows us to obstruct several 10 and
11-crossing knots from being unknotted by a single positive or negative twist.
We also use the Ozsv\'ath-Szab\'o tau invariant and the Rasmussen s invariant
to differentiate between the p- and q-untwisting numbers for certain p,q > 1.Comment: 21 pages, 11 figures; final version, accepted for publication in
Algebraic & Geometric Topolog
Questions to Luce Irigaray
This article traces the "dialogue" between the work of the philosophers Luce Irigaray and Emmanuel Levinas. It attempts to construct a more nuanced discussion than has been given to date of Irigaray's critique of Levinas, particularly as formulated in 'Questions to Emmanuel Levinas' (Irigaray 1991). It suggests that the concepts of the feminine and of voluptuosity articulated by Levinas have more to contribute to Irigaray's project of an ethics of sexual difference than she herself sometimes appears to think
Queering the Family: Fantasy and the performance of sexuality and gay relations in French cinema 1995-2000
This paper looks in detail at the representation of sexuality in the family in three films of the mid to late 1990s, Balasko’s Gazon maudit, Berliner’s Ma Vie en rose, and Giusti’s Pourquoi pas moi? Its double focus is the changing structure of the French family at the end of the twentieth century, considered against key political developments such as the pacte civil de solidarité (PaCS) of November 1999, and the cinematic fantasies in which these structural changes are envisioned. Fable, fantasy or anti-realism mark the endings of Gazon maudit and Pourquoi pas moi?, while sequences of childhood fantasy punctuate the entire length of Ma Vie en rose. No particular theoretical approach to fantasy is preferred, but the conclusion of the paper is that cinema may be a privileged cultural vehicle for politically enabling fantasy, and that the three films discussed demonstrate this where the French family is concerned
Bringing bodies back in: for a phenomenological and psychoanalytic film criticism of embodied cultural identity
This article reassesses the concept of identification in line with the increased importance phenomenology has taken on in film-philosophy of the 1990s and 2000s. In the 1970s and 1980s, a Lacanian psychoanalytic interpretation of identification dominated film theory and criticism, and spectatorial engagement with elements of films was understood as what psychoanalysis calls secondary identification – the identification with stable subject-positions (characters) in the film-text. But non-Lacanian psychoanalysis and Merleau-Ponty’s existential phenomenology offer film-philosophy a very different understanding of identification as a non image-based, ‘blind’, bodily affective tie that is established between spectators and what Vivian Sobchack describes as ‘the sense and sensibility of materiality itself’ (Sobchack 2004, 65). By first exploring how this more bodily (for psychoanalysis, primary) identification is theorized by psychoanalysts (Freud, Paul Schilder, Henri Wallon) and by film theorists (Kaja Silverman), the article proposes that film criticism make greater use of it in order to engage more meaningfully with the visible cultural specificities – size, skin colour, age, sex – of the images of bodies viewed on cinema screens. It is not just ‘the’ body that needs bringing back into thinking about film spectatorship, but culturally differentiated bodies, both on the screen and in the auditorium. A psychoanalytic and phenomenological film criticism of embodied cultural identity, one that attends to the materiality of the film and of the body-images and objects on the screen, may be the most culturally and politically useful successor to ‘screen’ theory of the 1970s and 1980s
Early Standard Model measurements with ATLAS
The measurement of Standard Model processes will be an important first step
towards exploiting the discovery potential of the Large Hadron Collider, the
highest energy accelerator ever built that will begin operation in the fall
2009. This paper presents a summary of the early physics analyses for
understanding the performance of the detector as well as the Standard Model at
the ATLAS experiment at 14 TeV centre of mass energy
Is sex comedy or tragedy? Directing desire and female auteurship in the cinema of Catherine Breillat
Measuring multivariate redundant information with pointwise common change in surprisal
The problem of how to properly quantify redundant information is an open question that has been the subject of much recent research. Redundant information refers to information about a target variable S that is common to two or more predictor variables Xi . It can be thought of as quantifying overlapping information content or similarities in the representation of S between the Xi . We present a new measure of redundancy which measures the common change in surprisal shared between variables at the local or pointwise level. We provide a game-theoretic operational definition of unique information, and use this to derive constraints which are used to obtain a maximum entropy distribution. Redundancy is then calculated from this maximum entropy distribution by counting only those local co-information terms which admit an unambiguous interpretation as redundant information. We show how this redundancy measure can be used within the framework of the Partial Information Decomposition (PID) to give an intuitive decomposition of the multivariate mutual information into redundant, unique and synergistic contributions. We compare our new measure to existing approaches over a range of example systems, including continuous Gaussian variables. Matlab code for the measure is provided, including all considered examples
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