LDPC codes from Singer cycles

The main goal of coding theory is to devise efficient systems to exploit the full capacity of a communication channel, thus achieving an arbitrarily small error probability. Low Density Parity Check (LDPC) codes are a family of block codes--characterised by admitting a sparse parity check matrix--with good correction capabilities. In the present paper the orbits of subspaces of a finite projective space under the action of a Singer cycle are investigated.Comment: 11 Page

Birds of a feather flock together:a dataset for Clock and Adcyap1 genes from migration genetics studies

Birds in seasonal habitats rely on intricate strategies for optimal timing of migrations. This is governed by environmental cues, including photoperiod. Genetic factors affecting intrinsic timekeeping mechanisms, such as circadian clock genes, have been explored, yielding inconsistent findings with potential lineage-dependency. To clarify this evidence, a systematic review and phylogenetic reanalysis was done. This descriptor outlines the methodology for sourcing, screening, and processing relevant literature and data. PRISMA guidelines were followed, ultimately including 66 studies, with 34 focusing on candidate genes at the genotype-phenotype interface. Studies were clustered using bibliographic coupling and citation network analysis, alongside scientometric analyses by publication year and location. Data was retrieved for allele data from databases, article supplements, and direct author communications. The dataset, version 1.0.2, encompasses data from 52 species, with 46 species for the Clock gene and 43 for the Adcyap1 gene. This dataset, featuring data from over 8000 birds, constitutes the most extensive cross-species collection for these candidate genes, used in studies investigating gene polymorphisms and seasonal bird migration.</p

Experimental test of Non-Commutative Quantum Gravity by VIP-2 Lead

Pauli Exclusion Principle (PEP) violations induced by space-time non-commutativity, a class of universality for several models of Quantum Gravity, are investigated by the VIP-2 Lead experiment at the Gran Sasso underground National Laboratory of INFN. The VIP-2 Lead experimental bound on the non-commutative space-time scale $\Lambda$ excludes $\theta$-Poincar\'e far above the Planck scale for non vanishing ``electric-like" components of $\theta_{\mu \nu}$, and up to $6.9 \cdot 10^{-2}$ Planck scales if they are null. Therefore, this new bound represents the tightest one so far provided by atomic transitions tests. This result strongly motivates high sensitivity underground X-ray measurements as critical tests of Quantum Gravity and of the very microscopic space-time structure.Comment: 13 pages, 2 figures. arXiv admin note: substantial text overlap with arXiv:2209.0007

Strongest atomic physics bounds on Non-Commutative Quantum Gravity Models

Investigations of possible violations of the Pauli Exclusion Principle represent critical tests of the microscopic space-time structure and properties. Space-time non-commutativity provides a class of universality for several Quantum Gravity models. In this context the VIP-2 Lead experiment sets the strongest bounds, searching for Pauli Exclusion Principle violating atomic-transitions in lead, excluding the $\theta$-Poincar\'e Non Commutative Quantum Gravity models far above the Planck scale for non-vanishing $\theta_{\mu \nu}$ ``electric-like'' components, and up to $6.9 \cdot 10^{-2}$ Planck scales if $\theta_{0i} = 0$.Comment: 7 pages, 2 figure

VIP-2 —High-Sensitivity Tests on the Pauli Exclusion Principle for Electrons

The VIP collaboration is performing high sensitivity tests of the Pauli Exclusion Principle for electrons in the extremely low cosmic background environment of the underground Gran Sasso National Laboratory INFN (Italy). In particular, the VIP-2 Open Systems experiment was conceived to put strong constraints on those Pauli Exclusion Principle violation models which respect the so-called Messiah–Greenberg superselection rule. The experimental technique consists of introducing a direct current in a copper conductor, and searching for the X-rays emission coming from a forbidden atomic transition from the L shell to the K shell of copper when the K shell is already occupied by two electrons. The analysis of the first three months of collected data (in 2018) is presented. The obtained result represents the best bound on the Pauli Exclusion Principle violation probability which fulfills the Messiah–Greenberg rule

High Precision Test of the Pauli Exclusion Principle for Electrons

The VIP-2 experiment aims to perform high precision tests of the Pauli Exclusion Principle for electrons. The method consists in circulating a continuous current in a copper strip, searching for the X radiation emission due to a prohibited transition (from the 2p level to the 1s level of copper when this is already occupied by two electrons). VIP already set the best limit on the PEP violation probability for electrons $\frac{1}{2} \beta^2 < 4.7 \times 10^{-29}$, the goal of the upgraded VIP-2 (VIolation of the Pauli Exclusion Principle-2) experiment is to improve this result of two orders of magnitude at least. The experimental apparatus and the results of the analysis of a first set of collected data will be presented

Search for a remnant violation of the Pauli exclusion principle in a Roman lead target

In this paper we report on the results of two analyses of the data taken with a dedicated VIP-Lead experiment at the Gran Sasso National Laboratory of the INFN. We use measurements taken in an environment that is especially well screened from cosmic rays, with a metal target made of “Roman lead” which is characterised by a low level of intrinsic radioactivity. The analyses lead to an improvement, on the upper bounds of the Pauli Exclusion Principle violation for electrons, which is more than one (four) orders of magnitude, when the electron-atom interactions are described in terms of scatterings (or close encounters) respectively

HIGH SENSITIVITY QUANTUM MECHANICS TESTS IN THE COSMIC SILENCE

The VIP experiment aims to perform high-precision tests of the Pauli Exclusion Principle for electrons in the extremely low cosmic background environment of the Underground Gran Sasso Laboratories of INFN (Italy). The experimental technique consists in introducing a DC current in a copper conductor, searching for K α PEP-forbidden atomic transitions when the K shell is already occupied by two electrons. The results of a preliminary data analysis, corresponding to the first run of the VIP-2 data taking (2016–2017), are presented. The experimental setup in the final configuration is described together with preliminary spectra from the 2019 data-taking campaign

Test of the Pauli Exclusion Principle in the VIP-2 Underground Experiment

The validity of the Pauli exclusion principle\u2014a building block of Quantum Mechanics\u2014is tested for electrons. The VIP (violation of Pauli exclusion principle) and its follow-up VIP-2 experiments at the Laboratori Nazionali del Gran Sasso search for X-rays from copper atomic transitions that are prohibited by the Pauli exclusion principle. The candidate events\u2014if they exist\u2014originate from the transition of a 2p orbit electron to the ground state which is already occupied by two electrons. The present limit on the probability for Pauli exclusion principle violation for electrons set by the VIP experiment is 4.7 710^ 1229. We report a first result from the VIP-2 experiment improving on the VIP limit, which solidifies the final goal of achieving a two orders of magnitude gain in the long run

NEW CONCEPTS IN TESTS OF THE PAULI EXCLUSION PRINCIPLE IN BULK MATTER

The standard scheme of several tests of the Pauli Exclusion Principle in bulk matter — both in the experiment and in the subsequent data analysis — has long been based on the seminal paper by E. Ramberg, G.A. Snow [Phys. Lett. B 238, 438 (1990)]. The ideas exposed in that paper are so simple and immediate that they have long gone unchallenged. However, while some of the underlying approximations are still valid, other parts of the article must be reconsidered. Here, we discuss some new concepts that are related to the motion of the electrons in the test metal (the “target” of the experiment) and which have been recently studied in the framework of the VIP-2 Collaboration