1,592 research outputs found
The method of exclusion (still) cannot identify specific mechanisms of cultural inheritance
The method of exclusion identifies patterns of distributions of behaviours and/or artefact forms among different groups, where these patterns are deemed unlikely to arise from purely genetic and/or ecological factors. The presence of such patterns is often used to establish whether a species is cultural or not—i.e. whether a species uses social learning or not. Researchers using or describing this method have often pointed out that the method cannot pinpoint which specific type(s) of social learning resulted in the observed patterns. However, the literature continues to contain such inferences. In a new attempt to warn against these logically unwarranted conclusions, we illustrate this error using a novel approach. We use an individual-based model, focused on wild ape cultural patterns—as these patterns are the best-known cases of animal culture and as they also contain the most frequent usage of the unwarranted inference for specific social learning mechanisms. We built a model that contained agents unable to copy specifics of behavioural or artefact forms beyond their individual reach (which we define as “copying”). We did so, as some of the previous inference claims related to social learning mechanisms revolve around copying defined in this way. The results of our model however show that non-copying social learning can already reproduce the defining—even iconic—features of observed ape cultural patterns detected by the method of exclusion. This shows, using a novel model approach, that copying processes are not necessary to produce the cultural patterns that are sometimes still used in an attempt to identify copying processes. Additionally, our model could fully control for both environmental and genetic factors (impossible in real life) and thus offers a new validity check for the method of exclusion as related to general cultural claims—a check that the method passed. Our model also led to new and additional findings, which we likewise discuss.European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation programme (Grant Agreement No 714658; STONECULT project)
Thermal correlators of anyons in two dimensions
The anyon fields have trivial -commutator for not integer.
For integer the commutators become temperature-dependent operator
valued distributions. The -point functions do not factorize as for quasifree
states.Comment: 14 pages, LaTeX (misprints corrected, a reference added
Form Factors and Correlation Functions of the Stress--Energy Tensor in Massive Deformation of the Minimal Models
The magnetic deformation of the Ising Model, the thermal deformations of both
the Tricritical Ising Model and the Tricritical Potts Model are governed by an
algebraic structure based on the Dynkin diagram associated to the exceptional
algebras (respectively for ). We make use of these underlying
structures as well as of the discrete symmetries of the models to compute the
matrix elements of the stress--energy tensor and its two--point correlation
function by means of the spectral representation method.Comment: 52 page
Maximizing the Conditional Expected Reward for Reaching the Goal
The paper addresses the problem of computing maximal conditional expected
accumulated rewards until reaching a target state (briefly called maximal
conditional expectations) in finite-state Markov decision processes where the
condition is given as a reachability constraint. Conditional expectations of
this type can, e.g., stand for the maximal expected termination time of
probabilistic programs with non-determinism, under the condition that the
program eventually terminates, or for the worst-case expected penalty to be
paid, assuming that at least three deadlines are missed. The main results of
the paper are (i) a polynomial-time algorithm to check the finiteness of
maximal conditional expectations, (ii) PSPACE-completeness for the threshold
problem in acyclic Markov decision processes where the task is to check whether
the maximal conditional expectation exceeds a given threshold, (iii) a
pseudo-polynomial-time algorithm for the threshold problem in the general
(cyclic) case, and (iv) an exponential-time algorithm for computing the maximal
conditional expectation and an optimal scheduler.Comment: 103 pages, extended version with appendices of a paper accepted at
TACAS 201
On the Form Factors of Relevant Operators and their Cluster Property
We compute the Form Factors of the relevant scaling operators in a class of
integrable models without internal symmetries by exploiting their cluster
properties. Their identification is established by computing the corresponding
anomalous dimensions by means of Delfino--Simonetti--Cardy sum--rule and
further confirmed by comparing some universal ratios of the nearby
non--integrable quantum field theories with their independent numerical
determination.Comment: Latex file, 35 pages with 5 Postscript figure
Mathematical structure of the temporal gauge
The mathematical structure of the temporal gauge of QED is critically
examined in both the alternative formulations characterized by either
positivity or regularity of the Weyl algebra. The conflict between time
translation invariance and Gauss law constraint is shown to lead to peculiar
features. In the positive case only the correlations of exponentials of fields
exist (non regularity), the space translations are not strongly continuous, so
that their generators do not exist, a theta vacuum degeneracy occurs,
associated to a spontaneous symmetry breaking. In the indefinite case the
spectral condition only holds in terms of positivity of the energy, gauge
invariant theta-vacua exist on the observables, with no extension to time
translation invariant states on the field algebra, the vacuum is faithful on
the longitudinal algebra and a KMS structure emerges. Functional integral
representations are derived in both cases, with the alternative between ergodic
measures on real random fields or complex Gaussian random fields.Comment: Late
SiPM and front-end electronics development for Cherenkov light detection
The Italian Institute of Nuclear Physics (INFN) is involved in the
development of a demonstrator for a SiPM-based camera for the Cherenkov
Telescope Array (CTA) experiment, with a pixel size of 66 mm. The
camera houses about two thousands electronics channels and is both light and
compact. In this framework, a R&D program for the development of SiPMs suitable
for Cherenkov light detection (so called NUV SiPMs) is ongoing. Different
photosensors have been produced at Fondazione Bruno Kessler (FBK), with
different micro-cell dimensions and fill factors, in different geometrical
arrangements. At the same time, INFN is developing front-end electronics based
on the waveform sampling technique optimized for the new NUV SiPM. Measurements
on 11 mm, 33 mm, and 66 mm NUV SiPMs
coupled to the front-end electronics are presentedComment: In Proceedings of the 34th International Cosmic Ray Conference
(ICRC2015), The Hague, The Netherlands. All CTA contributions at
arXiv:1508.0589
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