Strong singularity of singular masas in II₁ factors

A singular masa A in a II1 factor N is defined by the property that any unitary w ∈ N for which A=wAw* must lie in A. A strongly singular masa A is one that satisfies the inequality ||EA- EwAw*||∞,2 ≥||w- EA(w)||2 for all unitaries w ∈ N where EA is the conditional expectation of N onto A, and ||⋅||∞,2 is defined for bounded maps Φ : N → N by sup{||Φ (x)||2:x ∈ N,||x||≤1}. Strong singularity easily implies singularity, and the main result of this paper shows the reverse implication

Perturbations of C*-algebraic invariants

Kadison and Kastler introduced a metric on the set of all C*-algebras on a fixed Hilbert space. In this paper structural properties of C*-algebras which are close in this metric are examined. Our main result is that the property of having a positive answer to Kadison’s similarity problem transfers to close C*-algebras. In establishing this result we answer questions about closeness of commutants and tensor products when one algebra satisfies the similarity property. We also examine K-theory and traces of close C*-algebras, showing that sufficiently close algebras have isomorphic Elliott invariants when one algebra has the similarity property

The attitudinal work of news journalism images – a search for visual and verbal analogues

This paper is concerned with the potential of journalistic still images (photographs, pictorial layouts, artwork and political cartooning) to position readers/viewers to take a positive or negative view of the people, events and situations which are the subject matter of news journalism coverage. Referencing prior work by Economou (2009) and Swain (2012), it offers an account of the mechanisms, the particular visual qualities and compositional arrangements, by which such attitudinal effects are achieved. Its primary concern is exploring the grounds by which the mechanisms through which journalistic images activate positive or negative attitudes might be treated as analogous to related verbal expressions of attitude. In developing this discussion, it references and revisits the account of the language of evaluation developed within the Appraisal literature (Martin and White 2005). It proposes that in order to identify analogues to verbal expressions which, on the one hand, explicitly assert attitudinal assessments and which, on the other hand, activate attitudinal positions through implication and association, it is useful to attend to the following issues: (1) the salience or detectability of the author’s subjective presence in the text as the communicative agent who puts an attitudinal meaning into play; (2) the stability of the attitudinal associations of a given expression across multiple contexts of use; (3) the role of the reader in supplying attitudinal interpretations or inferences; (4) the terms under which relations of author-reader solidarity are negotiated or put at risk but the expression currently under consideration

Attitudinal Meanings, Translational Commensurability and Linguistic Relativity

The paper explores how insights developed within the Appraisal framework (Martin and White) into attitudinal meanings can contribute to some key, long-standing debates within translation studies and contrastive linguistics. It proposes that taxonomies developed within Appraisal for categorising diff erent types of positive and negative assessment provide a useful reference point for exploring how principled accounts of translational commensurability and incommensurability might be developed. Specifi cally, some methodologies are discussed for developing comparative maps of the systems of attitudinal valeur which operate in diff erent languages. Some implications for Appraisal theory itself resulting from the exploration of these cross-linguistic comparison issues are discussed. It is proposed that the taxonomies already formulated within the Appraisal literature to deal with attitudinal meaning may need to be extended in delicacy, if they are to be maximally useful in dealing with such issues.Este ensayo expone de qué manera puede el sistema de la Valoración (Martin and White) contribuir a los estudios de traducción y de lingüística contrastiva. Las taxonomías desarrolladas dentro de la Valoración en la categorización de los diferentes tipos de valor positivo o negativo ofrecen un punto de referencia importante para el estudio de los principios de la traducción. Se discuten de manera específi ca algunas metodologías para desarrollar mapas comparativos de los sistemas de valor actitudinal que operan en lenguas diferentes, con las consiguiente implicaciones para la teoría de la Valoración. Se sugiere además que las taxonomías ya establecidas dentro del sistema de la Valoración en el área de los signifi cados actitudinales deben de modifi carse para poder ser aplicadas con efi cacia en la comparación interlingüístic

The Tensor to Scalar Ratio of Phantom Dark Energy Models

We investigate the anisotropies in the cosmic microwave background in a class of models which possess a positive cosmic energy density but negative pressure, with a constant equation of state w = p/rho < -1. We calculate the temperature and polarization anisotropy spectra for both scalar and tensor perturbations by modifying the publicly available code CMBfast. For a constant initial curvature perturbation or tensor normalization, we have calculated the final anisotropy spectra as a function of the dark energy density and equation of state w and of the scalar and tensor spectral indices. This allows us to calculate the dependence of the tensor-to-scalar ratio on w in a model with phantom dark energy, which may be important for interpreting any future detection of long-wavelength gravitational waves.Comment: 5 pages, 4 figure

Quantum-fluctuation-induced repelling interaction of quantum string between walls

Quantum string, which was brought into discussion recently as a model for the stripe phase in doped cuprates, is simulated by means of the density-matrix-renormalization-group method. String collides with adjacent neighbors, as it wonders, owing to quantum zero-point fluctuations. The energy cost due to the collisions is our main concern. Embedding a quantum string between rigid walls with separation d, we found that for sufficiently large d, collision-induced energy cost obeys the formula \sim exp (- A d^alpha) with alpha=0.808(1), and string's mean fluctuation width grows logarithmically \sim log d. Those results are not understood in terms of conventional picture that the string is `disordered,' and only the short-wave-length fluctuations contribute to collisions. Rather, our results support a recent proposal that owing to collisions, short-wave-length fluctuations are suppressed, but instead, long-wave-length fluctuations become significant. This mechanism would be responsible for stabilizing the stripe phase

Renormalization-group running of the cosmological constant and its implication for the Higgs boson mass in the Standard Model

The renormalization-group equation for the zero-point energies associated with vacuum fluctuations of massive fields from the Standard Model is examined. Our main observation is that at any scale the running is necessarily dominated by the heaviest degrees of freedom, in clear contradistinction with the Appelquist & Carazzone decoupling theorem. Such an enhanced running would represent a disaster for cosmology, unless a fine-tuned relation among the masses of heavy particles is imposed. In this way, we obtain $m_H \simeq 550 GeV$ for the Higgs mass, a value safely within the unitarity bound, but far above the more stringent triviality bound for the case when the validity of the Standard Model is pushed up to the grand unification (or Planck) scale.Comment: 11 pages, LaTex2

Critical temperature for the two-dimensional attractive Hubbard Model

The critical temperature for the attractive Hubbard model on a square lattice is determined from the analysis of two independent quantities, the helicity modulus, $\rho_s$, and the pairing correlation function, $P_s$. These quantities have been calculated through Quantum Monte Carlo simulations for lattices up to $18\times 18$, and for several densities, in the intermediate-coupling regime. Imposing the universal-jump condition for an accurately calculated $\rho_s$, together with thorough finite-size scaling analyses (in the spirit of the phenomenological renormalization group) of $P_s$, suggests that $T_c$ is considerably higher than hitherto assumed.Comment: 5 pages, 6 figures. Accepted for publication in Phys. Rev.

Directional wind measurement derived from elastic backscatter lidar data in real time

The development of a capability to infer wind velocities simultaneously at a number of ranges along one direction in real time is described. The elastic backscatter lidar data used was obtained using the XM94 lidar, developed by Los Alamos National Laboratory for the US Army Chemical and Biological Detection Command. In some respects this problem is simpler than measuring wind velocities on meso-meteorological scales. Other requirements, particularly high temporal fidelity, have driven the development of faster software algorithms and suggested opportunities for the evolution of the hardware