8,252 research outputs found
Dark matter as integration constant in Horava-Lifshitz gravity
In the non-relativistic theory of gravitation recently proposed by Horava,
the Hamiltonian constraint is not a local equation satisfied at each spatial
point but an equation integrated over a whole space. The global Hamiltonian
constraint is less restrictive than its local version, and allows a richer set
of solutions than in general relativity. We show that a component which behaves
like pressureless dust emerges as an "integration constant" of dynamical
equations and momentum constraint equations. Consequently, classical solutions
to the infrared limit of Horava-Lifshitz gravity can mimic general relativity
plus cold dark matter.Comment: 16 pages; (non-)conservation equation for "dark matter" added (v2);
note added to comment on some recent preprints (v3); version accepted for
publication in PRD (v4
Comment on decay puzzle
We analize the current data on -lepton decays and show that they are
consistent with the Standard ModelComment: 5 pages, 1 figure (available from de authors), Latex, preprint
IFT-P.022/9
Algorithmic approach to adiabatic quantum optimization
It is believed that the presence of anticrossings with exponentially small
gaps between the lowest two energy levels of the system Hamiltonian, can render
adiabatic quantum optimization inefficient. Here, we present a simple adiabatic
quantum algorithm designed to eliminate exponentially small gaps caused by
anticrossings between eigenstates that correspond with the local and global
minima of the problem Hamiltonian. In each iteration of the algorithm,
information is gathered about the local minima that are reached after passing
the anticrossing non-adiabatically. This information is then used to penalize
pathways to the corresponding local minima, by adjusting the initial
Hamiltonian. This is repeated for multiple clusters of local minima as needed.
We generate 64-qubit random instances of the maximum independent set problem,
skewed to be extremely hard, with between 10^5 and 10^6 highly-degenerate local
minima. Using quantum Monte Carlo simulations, it is found that the algorithm
can trivially solve all the instances in ~10 iterations.Comment: 7 pages, 3 figure
Translation Revision: Correlating Revision Procedure and Error Detection
This article reports on an empirical study on translation revision. With the aim of investigating the possible link between revision procedure and quality, the research correlates an indicator of quality, error detection, with revision procedure. Error detection and revision procedure were studied drawing on a convergent parallel mixed-methods research design involving three different sources of data. Nine subjects performed a revision task and thus produced text data; their activities on the computer screen were captured and saved as video fi les; and retrospective interviews were conducted with the revisers upon completion of the task. Results show that the highest error detection scores were linked with a variety of revision procedures, but with one common denominator: the target text was consistently the point of departure. Revisers with high error detection scores thus engaged in various different revision procedures, but their focus of attention in the initial operations was the translation rather than the source text in all cases. Conversely, the revisers whose initial attention was directed towards the source text received the lowest error detection scores in the revision task
Translators and (lack of) power - a study of Danish company translators’ occupational status
Translators’ occupational status has received very little attention as a research topic in its own right. However, when we go through the translation literature, we frequently come across references to translation as a low-status profession
Short-Term Memory in the Production Phase of Sight Translation
This article reports on an empirical study on short-term memory in sight translation. The aim of the study was to test the hypothesis that sight translation requires the use of short-term memory during target-text production, as suggested by previous research. The hypothesis was tested on the basis of an experiment involving sight translation from Spanish into Danish and subsequent interviews with the translators. The data – the Spanish source text, seven sight translations into Danish, and the post-interviews – were analysed using both quantitative and qualitative methods, and the results of the study confirmed the hypothesis. In fact, the (quantitative) analyses of the sight-translated texts indicated that the subjects needed their short-term memory extensively during target-text production. However, the (qualitative) analyses of the interviews showed that the subjects had little awareness of this need
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