Classical Level Research Articles

A pilot study on canonical gravity with mass dimension one fermions

The mass dimension one (MDO) fermionic field is built on a complete set of dual-helicity eigenspinors of the charge conjugation operator, which obeys the statistic of Fermi-Dirac. These spinors are a potential candidates for the description of dark matter. The redefinition of the dual structure of this object holds a local adjacent theory and completely satisfies the Lorentz invariance. In this work, we investigate important aspects of the interaction of this fermion with gravity in the light of a canonical formulation in ADM formalism. We construct an action via tetrad fields using a manifold on a family of spacelike surfaces Σt that carries the MDO matter field, and additionally we propose a condition for the action to have a term associated with dark energy. We found the Hamiltonian and diffeomorphism constraints at the classical level for gravitational dynamics with the immersion of this material content in space-time, which leads us to the interpretation of the contribution of dark matter energy density, parallel to the lapse function of foliation and its directional flux of energy density in the hypersurface of manifold.

U(1) CS theory vs SL(2) CS formulation: Boundary theory and Wilson line

We first derive the boundary theory from the U(1) Chern-Simons theory. The boundary action on an n-sheet manifold appears from its back-reaction of the Wilson line. The reason is that the U(1) Chern-Simons theory can provide an exact effective action when introducing the Wilson line. The Wilson line in the pure AdS3 Einstein gravity is equivalent to entanglement entropy in the boundary theory up to classical gravity. The U(1) Chern-Simons theory deviates by a self-interaction term from the gauge formulation on the boundary. We also compare the Hayward term in the SL(2) Chern-Simons formulation to the Wilson line approach. Introducing two wedges can reproduce the entanglement entropy for a single interval at the classical level. We propose quantum generalization by combining the bulk and Hayward terms. The quantum correction of the partition function vanishes. In the end, we calculate the entanglement entropy for a single interval. The pure AdS3 Einstein gravity theory shows a shift of central charge by 26 at the one-loop level. The U(1) Chern-Simons theory does not show a shift from the quantum effect. The result is the same in the weak gravitational constant limit. The non-vanishing quantum correction shows that the Hayward term is incorrect.

Mass Generation and Gravity

Despite the success of the Higgs mechanism to account for the generation of masses of the Standard Model (SM) elementary particles, the ultimate nature and origin of “mass” remain open questions in contemporary physics. From a foundational perspective, mass should be fundamentally related to the gravitational interaction and, according to Mach, with the structure of the Universe. In the present letter, a fully dynamical mass generation mechanism induced by higher-order corrections in the GR Lagrangian is discussed. Notably, the vacuum energy plays a key role in this process, which applies to both vector bosons and fermions. We show that, at the classical level, the Higgs mechanism can be though of as a particular case of the present mechanism.

Geometrodynamical description of two-dimensional electrodynamics

Two-dimensional pure electrodynamics is mapped into two-dimensional gravity in the first-order formalism at classical and quantum levels. Due to the fact that the degrees of freedom of these two theories do not match, we are enforced to introduce extra fields from the beginning. These fields are introduced through a BRST exact boundary term, so they are harmless to the physical content of the theory. The map between electromagnetism and gravity fields generate a non-trivial Jacobian, which brings extra features (but also harmless to the physical content of the gravity theory) at quantum level.

Peningkatan Keterampilan Memerankan Tokoh dengan Menggunakan Metode Sosiodrama Siswa Sekolah Dasar

The background of the research is the low achievement of learning Indonesian in drama material for fifth grade students at Pahlawan Elementary School, Bangkinang District, Kampar Regency, Riau. The low results of learning to play drama because students are not trained by teachers in playing drama characters, so students experience difficulties in acting out drama with proper pronunciation, intonation, expression, and appreciation. Learning with the sociodrama method was chosen, because in addition to training students' courage to play drama, it also makes students active in learning and develops cooperation within students. The purpose of this study was to improve the skills of playing drama characters in fifth grade students of SD Pahlawan. The subjects in the study were teachers and fifth grade students at SD Pahlawan, Bangkinang District, Kampar Regency, Riau. The number of students is 17 children, consisting of 7 male students and 10 female students. This research is a Classroom Action Research (CAR). Data collection methods used are tests, observations, and documentation. Prior to conducting the research, the researcher conducted preliminary observation activities through interviews. The data analysis technique in this study is quantitative descriptive statistics, namely by finding the average. The results showed that learning the skills of playing drama characters using the sociodrama method could improve the skills of playing the characters of the fifth grade students of SD Pahlawan. Class average results in cycle I average student score of 67.47 with classical completeness of 70.58% (11 students). In cycle II, the average score of students increased again to 77 with a classical mastery level of 88.23% (15 students). From the data obtained, it can be concluded that the sociodrama method can improve learning outcomes and student activity in drama material.

Exact master equation for generalized quantum Brownian motion with momentum-dependent system-environment couplings

In this paper, we generalize the quantum Brownian motion to include momentum-dependent system-environment couplings. The conventional QBM model corresponds to the spacial case $W_k = V_k$. The generalized QBM is more complicated but the generalization is necessary. This is because the particle transition and the pair production between the system and the environment represent two very different physical processes, and usually cannot have the same coupling strengths. Thus, the conventional QBM model, which is well-defined at classical level, is hardly realized in real quantum physical world. We discuss the physical realizations of the generalized QBM in different physical systems, and derive its exact master equation for both the initial decoupled states and initial correlated states. The Hu-Paz-Zhang master equation of the conventional QBM model is reproduced as a special case. We find that the renormalized Brownian particle Hamiltonian after traced out all the environmental states induced naturally a momentum-dependent potential, which also shows the necessity of including the momentum-dependent coupling in the QBM Hamiltonian. In the Hu-Paz-Zhang master equation, such a renormalized potential is misplaced so that the correct renormalization Hamiltonian has not been found. With the exact master equation for both the initial decoupled and and initial correlated states, the issues about the initial jolt which is a long-stand problem in the Hu-Paz-Zhang master equation is also re-examined. We find that the so-called "initial jolt", which has been thought to be an artificial effect due to the use of the initial decoupled system-environment states, has nothing do to with the initial decoupled state. The new exact master equation for the generalized QBM also has the potential applications to photonics quantum computing.

The spacetime geometry of fixed-area states in gravitational systems

The concept of fixed-area states has proven useful for recent studies of quantum gravity, especially in connection with gravitational holography. We explore the Lorentz-signature spacetime geometry intrinsic to such fixed-area states in this paper. This contrasts with previous treatments which focused instead on Euclidean-signature saddles for path integrals that prepare such states. We analyze general features of fixed-area state geometries and construct explicit examples. The spacetime metrics are real at real times and have no conical singularities. With enough symmetry the classical metrics are in fact smooth, though more generally their curvatures feature power-law divergences along null congruences launched orthogonally from the fixed-area surface. While we argue that such divergences are not problematic at the classical level, quantum fields in fixed-area states feature stronger divergences. At the quantum level we thus expect fixed-area states to be well-defined only when the fixed-area surface is appropriately smeared.

Quantization of interacting Galilean field theories

We present the quantum field description of Galilean electrodynamics minimally coupled to massless Galilean fermion in (3 + 1)-dimensions. At classical level, the Lagrangian is obtained as a null reduction of a relativistic theory in one higher dimension. We use functional techniques to develop the quantum field description of the theory. Quantum corrections to the propagators and vertex are obtained upto first order and the theory is found to be renormalizable to this order. The beta function of the theory is found to grow linearly; the theory is not asymptotically free.

Quantum solvability of a nonlinear δ-type mass profile system: coupling constant quantization

In this paper, we discuss the quantum dynamics of a nonlinear system that admits temporally localized solutions at the classical level. We consider a general ordered position-dependent mass Hamiltonian in which the ordering parameters of the mass term are treated as arbitrary. The mass function here is singular at the origin. We observe that the quantum system admits bounded solutions but importantly the coupling parameter of the system gets quantized which has also been confirmed by the semiclassical study as well.

Limited Effect of Y Chromosome Variation on Coronary Artery Disease and Mortality in UK Biobank-Brief Report.

Background:The effect of genetic variation in the male-specific region of the Y chromosome (MSY) on coronary artery disease and cardiovascular risk factors has been disputed. In this study, we systematically assessed the association of MSY genetic variation on these traits using a kin-cohort analysis of family disease history in the largest sample to date.Methods:We tested 90 MSY haplogroups against coronary artery disease, hypertension, blood pressure, classical lipid levels, and all-cause mortality in up to 152 186 unrelated, genomically British individuals from UK Biobank. Unlike previous studies, we did not adjust for heritable lifestyle factors (to avoid collider bias) and instead adjusted for geographic variables and socioeconomic deprivation, given the link between MSY haplogroups and geography. For family history traits, subject MSY haplogroups were tested against father and mother disease as validation and negative control, respectively.Results:Our models find little evidence for an effect of any MSY haplogroup on cardiovascular risk in participants. Parental models confirm these findings.Conclusions:Kin-cohort analysis of the Y chromosome uniquely allows for discoveries in subjects to be validated using family history data. Despite our large sample size, improved models, and parental validation, there is little evidence to suggest cardiovascular risk in UK Biobank is influenced by genetic variation in MSY.

Seminal Microbiota of Idiopathic Infertile Patients and Its Relationship With Sperm DNA Integrity.

The development of new biomarkers for human male infertility is crucial to improve the diagnosis and the prognosis of this disease. Recently, seminal microbiota was shown to be related to sperm quality parameters, suggesting an effect in human fertility and postulating it as a biomarker candidate. However, its relationship to sperm DNA integrity has not been studied yet. The aim of the present study is to characterize the seminal microbiota of a western Mediterranean population and to evaluate its relationship to sperm chromatin integrity parameters, and oxidative stress. For that purpose, 14 samples from sperm donors and 42 samples from infertile idiopathic patients were obtained and were analyzed to assess the composition of the microbiota through full-length 16S rRNA gene sequencing (Illumina MiSeq platform). Microbial diversity and relative abundances were compared to classic sperm quality parameters (macroscopic semen parameters, motility, morphology and concentration), chromatin integrity (global DNA damage, double-stranded DNA breaks and DNA protamination status) and oxidative stress levels (oxidation-reduction potential). The seminal microbiota observed of these samples belonged to the phyla Firmicutes, Proteobacteria, Actinobacteria and Bacteroidetes. The most abundant genera were Finegoldia, Peptoniphilus, Anaerococcus, Campylobacter, Streptococcus, Staphylococcus, Moraxella, Prevotella, Ezakiella, Corynebacterium and Lactobacillus. To our knowledge, this is the first detection of Ezakiella genus in seminal samples. Two clusters of microbial profiles were built based on a clustering analysis, and specific genera were found with different frequencies in relation to seminal quality defects. The abundances of several bacteria negatively correlate with the sperm global DNA fragmentation, most notably Moraxella, Brevundimonas and Flavobacterium. The latter two were also associated with higher sperm motility and Brevundimonas additionally with lower oxidative-reduction potential. Actinomycetaceae, Ralstonia and Paenibacillus correlated with reduced chromatin protamination status and increased double-stranded DNA fragmentation. These effects on DNA integrity coincide in many cases with the metabolism or enzymatic activities of these genera. Significant differences between fertile and infertile men were found in the relative presence of the Propionibacteriaceae family and the Cutibacterium, Rhodopseudomonas and Oligotropha genera, which supports its possible involvement in male fertility. Our findings sustain the hypothesis that the seminal microbiome has an effect on male fertility.

Competition between decoherence and purification: Quaternionic representation and quaternionic fractals

We consider the competition between decoherence processes and an iterated quantum purification protocol. We show that this competition can be modelled by a nonlinear map onto the quaternion space. This nonlinear map has complicated behaviours, inducing a fractal border between the area of the quantum states dominated by the effects of the purification and the area of the quantum states dominated by the effects of the decoherence. The states on the border are unstable. The embedding in a 3D space of this border is like a quaternionic Julia set or a Mandelbulb with a fractal inner structure.Qubits are the resource of the quantum information as bits for the classical information, and are the main subject for future technologies as quantum computers. In contrast with bits, qubits exhibit states which are impossible at a classical level as Schrödinger cat states (the qubit is in a superposition of 0 and 1). These purely quantum properties are the resource to drastically increase the performance of the computing. But the noises of the environment generate a physical process called decoherence which suppresses the purely quantum properties. There is a protocol, called purification, which permits to restore the quantum behaviour. The result of the competition between a permanent decoherence process and a repeated purification protocol is not simple because this generates a chaotic process. We show that this one is a generalisation of the famous Julia map (which generates the famous fractals known as the Julia and the Mandelbrot sets). More precisely, in place of a map of the complex plane, the decoherence-purification competition map is a map of the quaternionic space (so-called Hamilton's number set, which are numbers which do not commute, i.e. zw=wz with z and w two quaternions). The decoherence-purification map generates 3D fractal sets similar to a Mandelbulb (3D generalisation of a Mandelbrot set) with a fractal inner structure.

Berry phase in the phase space worldline representation: The axial anomaly and classical kinetic theory

The Berry phase is analyzed for Weyl and Dirac fermions in a phase space representation of the worldline formalism. Kinetic theories are constructed for both at a classical level. Whereas the Weyl fermion case reduces in dimension, resembling a theory in quantum mechanics, the Dirac fermion case takes on a manifestly Lorentz covariant form. To achieve a classical kinetic theory for the non-Abelian Dirac fermion Berry phase a spinor construction of Barut and Zanghi is utilized. The axial anomaly is also studied at a quantum level. It is found that under an adiabatic approximation, which is necessary for facilitating a classical kinetic theory, the index of the Dirac operator for massless fermions vanishes. Even so, similarities of an axial rotation to an exact non-covariant Berry phase transform are drawn by application of the Fujikawa method to the Barut and Zanghi spinors on the worldline.

Machine learning molecular dynamics simulations toward exploration of high-temperature properties of nuclear fuel materials: case study of thorium dioxide

Predicting materials properties of nuclear fuel compounds is a challenging task in materials science. Their thermodynamical behaviors around and above the operational temperature are essential for the design of nuclear reactors. However, they are not easy to measure, because the target temperature range is too high to perform various standard experiments safely and accurately. Moreover, theoretical methods such as first-principles calculations also suffer from the computational limitations in calculating thermodynamical properties due to their high calculation-costs and complicated electronic structures stemming from f-orbital occupations of valence electrons in actinide elements. Here, we demonstrate, for the first time, machine-learning molecular-dynamics to theoretically explore high-temperature thermodynamical properties of a nuclear fuel material, thorium dioxide. The target compound satisfies first-principles calculation accuracy because f-electron occupation coincidentally diminishes and the scheme meets sampling sufficiency because it works at the computational cost of classical molecular-dynamics levels. We prepare a set of training data using first-principles molecular dynamics with small number of atoms, which cannot directly evaluate thermodynamical properties but captures essential atomistic dynamics at the high temperature range. Then, we construct a machine-learning molecular-dynamics potential and carry out large-scale molecular-dynamics calculations. Consequently, we successfully access two kinds of thermodynamic phase transitions, namely the melting and the anomalous lambda transition induced by large diffusions of oxygen atoms. Furthermore, we quantitatively reproduce various experimental data in the best agreement manner by selecting a density functional scheme known as SCAN. Our results suggest that the present scale-up simulation-scheme using machine-learning techniques opens up a new pathway on theoretical studies of not only nuclear fuel compounds, but also a variety of similar materials that contain both heavy and light elements, like thorium dioxide.

HIGH LEVEL OF THE AMOUNT OF ECG PEAKS SV1+RV5–V6 PREDICT NEW CASES OF HYPERTENSION IN THE ORGANIZED POPULATION OF THE PETROCHEMICAL INDUSTRY WORKERS

Objective: Identify risk factors for new cases of hypertension according to a 10-year prospective study of the organized population of the petrochemical industry workers in Belarus. Design and method: New cases of hypertension were revealed according to a 10-year prospective study in 2004/2014 in the organized population of 1,431 workers of petrochemical industry. In 2004 871 subjects with normal blood pressure were divided into two groups. The first group included 260 workers without adverse working factors, the second group included 611 workers with adverse working factors. The survey included standard questionnaires for detection of cardiovascular risk factors, anthropometric measurements, data from instrumental and laboratory examination. Results: According to a 10-year prospective study, a high incidence of hypertension in the studied population was established (37.5%: 31.5% in persons without adverse working factors and 40.1% in persons with adverse working factors) (p < 0.05). A significant positive relationship was found between the incidence of hypertension and work in harmful working conditions (p < 0.05), the strongest connection of which had psycho-physiological factors of labor intensity (p < 0.01). There was revealed significant positive association between the amount of ECG peaks SV1+RV5–V6 (>24 mm) and the frequency of new cases of hypertension adjusted for age, sex and factor of working conditions (df = 1; x2Wald = 33,0; p < 0,001). There were identified other significant factors affecting new cases of hypertension after adjusting for age, sex and factor of working conditions: systolic (p < 0.001) and diastolic blood pressure (p < 0.001), heredity (p < 0.01), absence of higher education (p < 0.001), smoking in the past and present (p < 0.001), alcohol abuse (p < 0.001), low physical activity (p < 0.001), body mass index (p < 0,001), level of salt taste threshold (p < 0,001), level of triglycerides (p < 0,01), glucose (p < 0,001) and GFR (p < 0,001) according to multifactorial regression analysis. Development of hypertension was also associated with a lack of recreational activities (p < 0.001). Conclusions: In addition to classical risk factors level of the amount of ECG peaks SV1+RV5–V6 > 24 mm is a new predictor of development of hypertension in the Belarusian organized population.

Symplectic quantization of multifield generalized Proca electrodynamics

We explicitly carry out the symplectic quantization of a family of multifield generalized Proca (GP) electrodynamics theories. In the process, we provide an independent derivation of the so-called secondary constraint enforcing relations---consistency conditions that significantly restrict the allowed interactions in multifield settings already at the classical level. Additionally, we unveil the existence of quantum consistency conditions, which apply in both single- and multifield GP scenarios. Our newly found conditions imply that not all classically well-defined (multi-)GP theories are amenable to quantization. The extension of our results to the most general multi-GP class is conceptually straightforward, albeit algebraically cumbersome.

Spontaneous symmetry breakings in the singlet scalar Yukawa model within the auxiliary field method

The aim of this work is to investigate the occurrence of two different spontaneous symmetry breakings at two levels of the description of fermion-scalar field model, by means of a set of gap equations and with a background field effective action. For that, we consider the Yukawa model, as a toy model for interactions between nonmassive fermions intermediated by a self-interacting real scalar field. This model has at stake two symmetries at the classical level that, as we know, might be spontaneously or dynamically broken with mass generation for the particles. The auxiliary field method is considered and it produces coupled renormalized gap equations. The effective action is then written with quantum contributions by the external background field method. We brought to light how the renormalization procedure affects the physical gaps, investigate its properties, and discuss the connection between the auxiliary fields not only to define composite states but also to compute the effective action.

Nonseparable States of Light: From Quantum to Classical

AbstractControlling the various degrees‐of‐freedom (DoFs) of structured light at both quantum and classical levels is of paramount importance in optics. It is a conventional paradigm to treat diverse DoFs separately in light shaping. While, the more general case of nonseparable states of light, in which two or more DoFs are coupled in a nonseparable way, has become topical recently. Importantly, classical nonseparable states of light are mathematically analogue to quantum entangled states. Such similarity has hatched attractive studies in structured light, for example, the spin‐orbit coupling in vector beams. However, nonseparable classical states of light are still treated in a fragmented fashion, while its forms are not limited by vector beams and its potential is certainly not fully exploited. For instance, exotic space‐time coupled pulses open nontrivial light shaping toward ultrafast time scales, and ray‐wave geometric beams provide new dimensions in optical manipulations. Here, a bird's eye view on the rapidly growing but incoherent body of work on general nonseparable states involving various DoFs of light is provided and a unified framework for their classification and tailoring, providing a perspective on new opportunities for both fundamental science and applications, is introduced.

Dynamic difficulty adjustment technique-based mobile vocabulary learning game for children with autism spectrum disorder

This article describes the design, implementation, and evaluation of an educational mobile game. Pickstar aims to make vocabulary learning training more accessible to families with ASD, in a way that increases engagement by offering a multisensory experience and by adapting to the level of each player. The game includes two learning approaches: the classical levels advancement approach where the levels gradually increase in difficulty and Dynamic Difficulty Adjustment (DDA) approach that adapts to the skill level of the player as determined via feature extraction. Through the AdaptiveMiniMax algorithm, Pickstar’s DDA feature ensures that everyone has the same winning rate of approximately 70%, encouraging players of all levels to play again. The engagement rate of children with ASD in the learning process was 88.4% higher for DDA compared with classical levels. Usability evaluation of Pickstar, based on ISO 25062:2006, on caregiver interviews concluded that Pickstar not only decreases caregivers’ teaching and assessment loads, but also increases the time children spend on learning. Caregiver interviews, usability testing, and engagement assessments show that Pickstar can be used with minimal guidance to improve vocabulary skills of individuals with ASD and can mitigate caregiver problems in accessing good-quality, engaging, and affordable education for their children.

Tranexamic acid alters the immunophenotype of phagocytes after lower limb surgery

BackgroundTranexamic acid (TXA) is an antifibrinolytic agent frequently used in elective surgery to reduce blood loss. We recently found it also acts as a potent immune-modulator in patients undergoing cardiac surgery.MethodsPatients undergoing lower limb surgery were enrolled into the “Tranexamic Acid in Lower Limb Arthroplasty” (TALLAS) pilot study. The cellular immune response was characterised longitudinally pre- and post-operatively using full blood examination (FBE) and comprehensive immune cell phenotyping by flowcytometry. Red blood cells and platelets were determined in the FBE and levels of T cell cytokines and the plasmin-antiplasmin complex determined using ELISA.ResultsTXA administration increased the proportion of circulating CD141+ conventional dendritic cells (cDC) on post-operative day (POD) 3. It also reduced the expression of CD83 and TNFR2 on classical monocytes and levels of circulating IL-10 at the end of surgery (EOS) time point, whilst increasing the expression of CCR4 on natural killer (NK) cells at EOS, and reducing TNFR2 on POD-3 on NK cells. Red blood cells and platelets were decreased to a lower extent at POD-1 in the TXA group, representing reduced blood loss.ConclusionIn this investigation we have extended our examination on the immunomodulatory effects of TXA in surgery by also characterising the end of surgery time point and including B cells and neutrophils in our immune analysis, elucidating new immunophenotypic changes in phagocytes as well as NK cells. This study enhances our understanding of TXA-mediated effects on the haemostatic and immune response in surgery, validating changes in important functional immune cell subsets in orthopaedic patients.