3,134 research outputs found
Analytic Torsion on Hyperbolic Manifolds and the Semiclassical Approximation for Chern-Simons Theory
The invariant integration method for Chern-Simons theory for gauge group
SU(2) and manifold \Gamma\H^3 is verified in the semiclassical approximation.
The semiclassical limit for the partition function associated with a connected
sum of hyperbolic 3-manifolds is presented. We discuss briefly L^2 - analytical
and topological torsions of a manifold with boundary.Comment: 12 pages, LaTeX fil
Edge local complementation for logical cluster states
A method is presented for the implementation of edge local complementation in
graph states, based on the application of two Hadamard operations and a single
controlled-phase (CZ) gate. As an application, we demonstrate an efficient
scheme to construct a one-dimensional logical cluster state based on the
five-qubit quantum error-correcting code, using a sequence of edge local
complementations. A single physical CZ operation, together with local
operations, is sufficient to create a logical CZ operation between two logical
qubits. The same construction can be used to generate any encoded graph state.
This approach in concatenation may allow one to create a hierarchical quantum
network for quantum information tasks.Comment: 15 pages, two figures, IOP styl
Machine Learning and Irresponsible Inference: Morally Assessing the Training Data for Image Recognition Systems
Just as humans can draw conclusions responsibly or irresponsibly, so too can computers. Machine learning systems that have been trained on data sets that include irresponsible judgments are likely to yield irresponsible predictions as outputs. In this paper I focus on a particular kind of inference a computer system might make: identification of the intentions with which a person acted on the basis of photographic evidence. Such inferences are liable to be morally objectionable, because of a way in which they are presumptuous. After elaborating this moral concern, I explore the possibility that carefully procuring the training data for image recognition systems could ensure that the systems avoid the problem. The lesson of this paper extends beyond just the particular case of image recognition systems and the challenge of responsibly identifying a personâs intentions. Reflection on this particular case demonstrates the importance (as well as the difficulty) of evaluating machine learning systems and their training data from the standpoint of moral considerations that are not encompassed by ordinary assessments of predictive accuracy
Improvement of stabilizer based entanglement distillation protocols by encoding operators
This paper presents a method for enumerating all encoding operators in the
Clifford group for a given stabilizer. Furthermore, we classify encoding
operators into the equivalence classes such that EDPs (Entanglement
Distillation Protocol) constructed from encoding operators in the same
equivalence class have the same performance. By this classification, for a
given parameter, the number of candidates for good EDPs is significantly
reduced. As a result, we find the best EDP among EDPs constructed from [[4,2]]
stabilizer codes. This EDP has a better performance than previously known EDPs
over wide range of fidelity.Comment: 22 pages, 2 figures, In version 2, we enumerate all encoding
operators in the Clifford group, and fix the wrong classification of encoding
operators in version
ENOBIO - First tests of a dry electrophysiology electrode using carbon nanotubes
We describe the development and first tests of Enobio, a dry electrode sensor
concept for biopotential applications. In the proposed electrodes, the tip of
the electrode is covered with a forest of multi-walled CNTs that can be coated
with Ag/AgCl to provide ionic-electronic transduction. The CNT brush-like
structure is to penetrate the outer layers of the skin improving electrical
contact as well as increae the contact surface area. In this paper, we report
the results of the first tests of this concept -- immersion on saline solution
and pig skin signal detection. These indicate performance on a par with state
of the art research-oriented wet electrodes.Comment: Submitted and accepted at the 28th IEEE EMBS International
Conference, New York City, August 31st-September 3rd, 2006. Figures updated
with proper filtering and averagin
Perturbative framework for the pi(+)pi(-) atom
The perturbative framework is developed for the calculation of the pi(+)pi(-)
atom characteristics on the basis of the field-theoretical Bethe-Salpeter
approach. A closed expression for the first-order correction to the pi(+)pi(-)
atom lifetime has been obtained.Comment: 8 pages, LaTeX-fil
The relation between self-event connections and personality functioning in youth with severe psychopathology
OBJECTIVE: One way in which individuals construct their narrative identity is by making selfâevent connections, which are often linked to better functioning. Being unable to make connections is related to identity discontinuity and psychopathology. Work in the general population corroborates this association, but also highlights the importance of focusing on specific aspects of these connections and on vulnerable populations. METHOD: We examined the association of selfâevent connections with personality functioning in youth with severe psychopathology (crossâsectional N = 228, M (age) = 19.5, longitudinal N = 84), and the role of event and connection valence in the subsample of youth who made a connection (n = 188 and n = 68). Negative affectivity was controlled for in all models. RESULTS: We found no evidence that selfâevent connections, nor connection valence and its interaction with event valence, are related to functioning. Positive event valence was associated with better functioning. Higher negative affectivity was strongly linked to lower functioning and explained the relation between event valence and functioning. No longitudinal associations emerged. CONCLUSIONS: These findings show that for youth with severe psychopathology making selfâevent connections may not be associated with better functioning. Moreover, negative affectivity may be a distal predictor of both event valence and functioning
Algebraic invariants of five qubits
The Hilbert series of the algebra of polynomial invariants of pure states of
five qubits is obtained, and the simplest invariants are computed.Comment: 4 pages, revtex. Short discussion of quant-ph/0506073 include
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