575 research outputs found
Einstein's Local Realism and the Realistic Interpretation of the Wave Function
We review the different kinds of realism debates in philosophy and particularly in philosophy of science, then discussing in which ways they may be empirically significant, and analyzing criteria for a (non sharp nor absolute) demarcation between science and philosophy. We then outline two main realistic approaches in the foundations of quantum mechanics, de Broglie’s and Bohm’s “wave existential realism”, and Einstein, Podolski and Rosen’s “properties independence realism”. Both appear quite appealing, but neither has been completely successful. We then draw inspiration from them to propose a complementarity experiment, whereby the reality of quantum waves turns out to be grounded on “non local” properties of quantum systems. In this frame, empirical evidence appears to be relevant both to philosophy and science
Top-Down Causation by Information Control: From a Philosophical Problem to a Scientific Research Program
It has been claimed that different types of causes must be considered in
biological systems, including top-down as well as same-level and bottom-up
causation, thus enabling the top levels to be causally efficacious in their own
right. To clarify this issue, important distinctions between information and
signs are introduced here and the concepts of information control and
functional equivalence classes in those systems are rigorously defined and used
to characterise when top down causation by feedback control happens, in a way
that is testable. The causally significant elements we consider are equivalence
classes of lower level processes, realised in biological systems through
different operations having the same outcome within the context of information
control and networks.Comment: Revised version to meet referee's comments, and responding to a paper
by Wegscheid et al that was not mentioned in the previous version. 23 pages,
9 figure
Limit quantum efficiency for violation of Clauser-Horne Inequality for qutrits
In this paper we present the results of numerical calculations about the
minimal value of detection efficiency for violating the Clauser - Horne
inequality for qutrits. Our results show how the use of non-maximally entangled
states largely improves this limit respect to maximally entangled ones. A
stronger resistance to noise is also found.Comment: Phys. Rev. A in pres
Visualizing the Quantum Interaction Picture in Phase Space
We illustrate the correspondence between the quantum Interaction
Picture-evolution of the state of a quantum system in Hilbert space and a
combination of local and global transformations of its Wigner function in phase
space. To this aim, we consider the time-evolution of a quantized harmonic
oscillator driven by both a linear and a quadratic (in terms of bosonic
creation and annihilation operators) potentials and employ the Magnus series to
derive the exact form of the time-evolution operator. In this case, the
Interaction Picture corresponds to a local transformation of phase
space-reference frame into the one that is co-moving with the Wigner function.Comment: Submitted to New Journal of Physic
Lymphedema after pelvic and para-aortic lymphadenectomy—results of a systematic evaluation in patients with cervical and endometrial carcinoma
Background Lymphedema is a frequent complication after surgical treatment in gynecological oncology with substantial impact on patients ' Quality of Life (QoL). Little is known about screening instruments and prevention. Primary objective was to develop and validate the German version of a 13 items screening questionnaire (SQ) developed by Yost et al. to provide a valid instrument for early diagnosis of lower extremity lymphedema (LEL). Methods After translation the SQ was used in pt. with cervical or endometrial cancer who underwent pelvic/paraaortic Lymphadenectomy. Sensitivity and specifity were analysed regarding possible prediction and influencing factors of LEL. Results 67 pt. had LEL (N = 128). Nearly 50% of women in each group (38 in LEL + e 30 in LEL - ) had a body mass index (BMI) > 30 kg/m(2). Number of removed lymphnodes, radiotherapy and were significantly associated with development of LEL. Translated Mayo Clinic questionnaire can be used with reliable specifity and sensitivity. Four additional questions improved the diagnostic accuracy of the SQ. Conclusions The translated SQ is a valuable and predictive tool for screening and early detection of LEL in Gynecological cancer surgery and can even improved by adding simple questions
Damage Detection and Localization on Real Structures Subjected to Strong Motion Earthquakes Using the Curvature Evolution Method: The Navelli (Italy) Case Study
In recent years, structural health monitoring (SHM) has received increasing interest from both research and professional engineering communities. This is due to the limitations related to the use of traditional methods based on visual inspection for a rapid and effective assessment of structures and infrastructures when compared with the great potential offered by newly developed automatic systems. Most of these kinds of systems allow the continuous estimation of structural modal properties that are strictly correlated to the mechanical characteristics of the monitored structure. These can change as a result of material deterioration and structural damage related to earthquake shaking. Furthermore, a suitable configuration of a dense sensor network in a real-time monitoring system can allow to detect and localize structural and non-structural damage by comparing the initial and a final state of the structure after a critical event, such as a relevant earthquake. In this paper, the modal curvature evaluation method, used for damage detection and localization on framed structures, considering the mode curvature variation due to strong earthquake shaking, is further developed. The modified approach is validated by numerical and experimental case studies. The extended procedure, named "Curvature Evolution Method" (CEM), reduces the required computing time and the uncertainties in the results. Furthermore, in this work, an empirical relationship between curvature variation and damage index has been defined for both bare and infilled frames
Metastability of Asymptotically Well-Behaved Potential Games
One of the main criticisms to game theory concerns the assumption of full
rationality. Logit dynamics is a decentralized algorithm in which a level of
irrationality (a.k.a. "noise") is introduced in players' behavior. In this
context, the solution concept of interest becomes the logit equilibrium, as
opposed to Nash equilibria. Logit equilibria are distributions over strategy
profiles that possess several nice properties, including existence and
uniqueness. However, there are games in which their computation may take time
exponential in the number of players. We therefore look at an approximate
version of logit equilibria, called metastable distributions, introduced by
Auletta et al. [SODA 2012]. These are distributions that remain stable (i.e.,
players do not go too far from it) for a super-polynomial number of steps
(rather than forever, as for logit equilibria). The hope is that these
distributions exist and can be reached quickly by logit dynamics.
We identify a class of potential games, called asymptotically well-behaved,
for which the behavior of the logit dynamics is not chaotic as the number of
players increases so to guarantee meaningful asymptotic results. We prove that
any such game admits distributions which are metastable no matter the level of
noise present in the system, and the starting profile of the dynamics. These
distributions can be quickly reached if the rationality level is not too big
when compared to the inverse of the maximum difference in potential. Our proofs
build on results which may be of independent interest, including some spectral
characterizations of the transition matrix defined by logit dynamics for
generic games and the relationship of several convergence measures for Markov
chains
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