Fundamental Scale Research Articles

W-Boson Mass Anomaly as a Manifestation of Spontaneously Broken Additional SU(2) Global Symmetry on a New Fundamental Scale

Recently, the CDF Collaboration has announced a new precise measurement of the W-boson mass MW that deviates from the Standard Model (SM) prediction by 7σ. The discrepancy in MW is about ΔW ≃ 70 MeV and is probably caused by a beyond the SM physics. Within a certain scenario of extension of the SM, we obtain the relation ΔW ≃ 3α8πMW ≃ 70 MeV, where α is the electromagnetic fine structure constant. The main conjecture is the appearance of longitudinal components of the W-bosons as the Goldstone bosons of a spontaneously broken additional SU(2) global symmetry at distances much smaller than the electroweak symmetry breaking scale rEWSB. We argue that within this scenario, the masses of charged Higgs scalars can obtain an electromagnetic radiative contribution which enhances the observed value of MW± with respect to the usual SM prediction. Our relation for ΔW follows from the known one-loop result for the corresponding effective Coleman–Weinberg potential in combination with the Weinberg sum rules.

Generalized Extended Uncertainty Principle Black Holes: Shadow and Lensing in the Macro- and Microscopic Realms

Motivated by the recent study about the extended uncertainty principle (EUP) black holes, we present in this study its extension called the generalized extended uncertainty principle (GEUP) black holes. In particular, we investigated the GEUP effects on astrophysical and quantum black holes. First, we derive the expression for the shadow radius to investigate its behavior as perceived by a static observer located near and far from the black hole. Constraints to the large fundamental length scale, L*, up to two standard deviations level were also found using the Event Horizont Telescope (EHT) data: for black hole Sgr. A*, L*=5.716×1010 m, while for M87* black hole, L*=3.264×1013 m. Under the GEUP effect, the value of the shadow radius behaves the same way as in the Schwarzschild case due to a static observer, and the effect only emerges if the mass, M, of the black hole is around the order of magnitude of L* (or the Planck length, lPl). In addition, the GEUP effect increases the shadow radius for astrophysical black holes, but the reverse happens for quantum black holes. We also explored GEUP effects to the weak and strong deflection angles as an alternative analysis. For both realms, a time-like particle gives a higher value for the weak deflection angle. Similar to the shadow, the deviation is seen when the values of L* and M are close. The strong deflection angle gives more sensitivity to GEUP deviation at smaller masses in the astrophysical scenario. However, the weak deflection angle is a better probe in the micro world.

There is no universal acceleration scale in galaxies

Abstract Recently, many studies have seemed to reveal the existence of some correlations between dark matter and baryonic matter. In particular, the unexpected tight radial acceleration relation (RAR) discovered in rotating galaxies has drawn a lot of attention. The RAR suggests the existence of a universal and fundamental acceleration scale in galaxies, which seems to challenge the ΛCDM model and favor some modified gravity theories. A large debate about whether RAR is compatible with the ΛCDM model has arisen. Here, by analyzing the high-quality velocity dispersion profiles of 13 E0-type elliptical galaxies in the SDSS-IV MaNGA sample and assuming a power-law function of radius r for the 3D velocity dispersion in each galaxy, we report the RAR for E0-type elliptical galaxies and we show that the resultant RAR has more than 5σ deviations from the RAR in late-type galaxies. This new RAR provides an independent probe to falsify the existence of any universal acceleration scale in galaxies. Our result significantly challenges those modified gravity theories that suggest the existence of any universal acceleration scale.

Hawking temperature for 4D-Einstein-Gauss-Bonnet black holes from uncertainty principle

Inspired by string theory, Heisenberg's uncertainty principle can be generalized to include the photon-electron gravitational interaction, which leads to the Generalized Uncertainty Principle (GUP). Although GUP considers gravitational uncertainty at the minimum fundamental length scale in physics, it does not consider the effects of spacetime curvature on quantum mechanical uncertainty relations. The Extended Uncertainty Principle (EUP) is a generalization of Heisenberg's Uncertainty Principle that, unlike the GUP, applies to large length scales. GEUP is also a linear combination of EUP and GUP that creates minimal uncertainty on large length scales. The Einstein-Gauss-Bonnet theory (EGB) can be considered as one of the most promising candidates for modified gravity. In this paper, by using GUP, EUP, and GEUP, we intend to obtain the Hawking temperature of a four-dimensional EGB black hole in the asymptotically flat and (Anti)-de Sitter spacetime. We show that coupling constant, cosmological constant, mass, and radius significantly affect Hawking temperature and decrease or increase Hawking temperature depending on the chosen horizons.

On the reconstruction problem in quantum gravity

Path integrals and the Wilsonian renormalization group provide two complementary computational tools for investigating continuum approaches to quantum gravity. The starting points of these constructions utilize a bare action and a fixed point of the renormalization group flow, respectively. While it is clear that there should be a connection between these ingredients, their relation is far from trivial. This results in the so-called reconstruction problem. In this work, we demonstrate that the map between these two formulations does not generate non-localities at quadratic order in the background curvature. At this level, the bare action in the path integral and the fixed-point action obtained from the Wilsonian renormalization group differ by local terms only. This conclusion does not apply to theories coming with a physical ultraviolet cutoff or a fundamental non-locality scale.

Molecular Simulation of Cement-Based Materials and Their Properties

Hydrated cement is one of the complex composite systems due to the presence of multi-scale phases with varying morphologies. Calcium silicate hydrate, which is the principal binder phase in the hydrated cement, is responsible for the stiffness, strength, and durability of Portland cement concrete. To understand the mechanical and durability behavior of concrete, it is important to investigate the interactions of hydrated cement phases with other materials at the nanoscale. In this regard, the molecular simulation of cement-based materials is an effective approach to study the properties and interactions of the cement system at the fundamental scale. Recently, many studies have been published regarding atomistic simulations to investigate the cement phases to define/explain the microscopic physical and chemical properties, thereby improving the macroscopic performance of hardened binders. The research in molecular simulation of cementitious systems involves researchers with multidisciplinary backgrounds, mainly in two areas: ① cement chemistry, where the hydration reactions govern most of the chemical and physical properties at the atomic scale; and ② computational materials science and engineering, where the bottom-up approach is required. The latter approach is still in its infancy, and as such, a study of the prevailing knowledge is useful, namely through an exhaustive literature review. This state-of-the-art report provides a comprehensive survey on studies that were conducted in this area and cites the important findings.

Probing the mesoscopic size limit of quantum anomalous Hall insulators

The inelastic scattering length (Ls) is a length scale of fundamental importance in condensed matters due to the relationship between inelastic scattering and quantum dephasing. In quantum anomalous Hall (QAH) materials, the mesoscopic length scale Ls plays an instrumental role in determining transport properties. Here we examine Ls in three regimes of the QAH system with distinct transport behaviors: the QAH, quantum critical, and insulating regimes. Although the resistance changes by five orders of magnitude when tuning between these distinct electronic phases, scaling analyses indicate a universal Ls among all regimes. Finally, mesoscopic scaled devices with sizes on the order of Ls were fabricated, enabling the direct detection of the value of Ls in QAH samples. Our results unveil the fundamental length scale that governs the transport behavior of QAH materials.

Thermodynamic studies of the rainbow gravity-inspired higher-dimensional Schwarzschild black hole: Snyder–de Sitter model

One of the staple objectives of theoretical physics is to establish a reliable theory of quantum gravity. To achieve this goal, some fundamental scales are proposed in the modern era, e.g. two scales are proposed in the Snyder–de Sitter model. These two scales relate to measurement limits of the position and momentum. In this paper, we study the thermodynamic properties of the higher-dimensional Schwarzschild black hole in the context of rainbow gravity in the Snyder–de Sitter model within the presence and absence of rainbow gravity and compare our results for [Formula: see text] with the results which are already derived in the previous literature [B. Hamil and B. C. Lütfüoğlu, Int. J. Geom. Methods Mod. Phys. 19, 2250047 (2022)]. We find the existence of the remnant temperature of the concerned black hole. Unlike the four-dimensional Schwarzschild black hole, the black hole in higher dimensions [Formula: see text] has two remnant temperatures. Moreover, we observe that in the rainbow gravity background a nonzero lower bound value of the temperature of the black hole exists. Finally, we analyze the thermal stability remnant conditions of the black hole by computing the heat capacity within this model.

Cosmological Perturbations in Bouncing Cosmologies and the Case of the Pre-Big Bang Scenario

Pre-Big Bang cosmology inspired generations of cosmologists in attempts to cure the initial Big Bang singularity using a fundamental length scale as proposed by string theory. The existence of a phase of collapse/inflation with increasing curvature followed by a cosmic bounce has been proposed as an alternative to standard inflation in the solution of the horizon and curvature problems. However, the generation of a nearly scale-invariant spectrum of perturbations is not an automatic prediction of such scenarios. In this paper, I review some general statements about the evolution of perturbations in bouncing cosmologies and some historically significant attempts to reconcile the predicted spectra with the observations. Bouncing cosmologies and, in particular, the pre-Big Bang scenario stand as viable, although more complicated, alternatives to inflation that may still help solve current theoretical and observational tensions.

Effectiveness of Psychosocial Rehabilitation: Innovative Method of Results Assessment

Background: The main problem of evaluating the effectiveness of psychosocial rehabilitation (PSR) is incorrect methods of processing psychometric data obtained with the help of appropriate tools (scales and questionnaires), which are standard used to measure the effectiveness of interventions within the framework of the implementation of PSR procedures. The purpose of the study: 1) а systematic analysis of the problems of assessing the severity of mental disorders and the effectiveness of subsequent PSR; 2) development of cardinal algorithms for processing the initial expert information in order to obtain appropriate numerical criteria for the effectiveness of the PSR. Material and methods: a systematic analysis of domestic and foreign publications, based on the results of their own research on the problems of assessing patients’ conditions, as well as evaluating the effectiveness of a comprehensive long-term PSR program for people with schizophrenia and schizophrenic spectrum disorders in various forms of care (public organization, day hospital, hospital). As methods of information processing, clinical-psychopathological, psychometric, as well as methods of system analysis and the analytic hierarchy process (AHP) were used. Results: an innovative methodology and algorithms for processing expert clinical, psychopathological and psychometric information based on the AHP apparatus have been developed to develop criteria for the effectiveness of PSR. The cardinal difference between the proposed approach and the rank methods of processing initial information is that the results of processing initial expert information are obtained in the fundamental scale of AHP (numerical scale), which ensures the correct integration of psychometric and psychosocial characteristics of patients when considering diagnostic procedures, psychosocial therapy and rehabilitation. Conclusions: the calculations are based on expert assessments of the weight of areas of impaired functioning of patients and the corresponding changes in psychosocial characteristics. This ensures the universality of the methodology and algorithms for evaluating the effectiveness of any rehabilitation interventions: from psychosocial to physiotherapy.

Taylor Microscale and Effective Reynolds Number near the Sun from PSP

The Taylor microscale is a fundamental length scale in turbulent fluids, representing the end of fluid properties and onset of dissipative processes. The Taylor microscale can also be used to evaluate the Reynolds number in classical turbulence theory. Although the solar wind is weakly collisional, it approximately behaves as a magnetohydrodynamic (MHD) fluid at scales larger than the kinetic scale. As a result, classical fluid turbulence theory and formalisms are often used to study turbulence in the MHD range. Therefore, a Taylor microscale can be used to estimate an effective Reynolds number in the solar wind. NASA’s Parker Solar Probe (PSP) has reached progressively closer to the Sun than any other spacecraft before. The collected data have revealed many new findings in the near-Sun solar wind. Here, we use the PSP data to estimate the Taylor microscale and effective Reynolds number near the Sun. We find that the Taylor microscale and Reynolds number are small compared to the corresponding near-Earth values, indicating a solar wind that has been less processed by turbulence, with very small-scale dissipative processes near the Sun.

Fundamental length scale and the bending of light in a gravitational field

The canonical approach to quantizing quantum gravity is understood to suffer from pathological non-renomalizability. Nevertheless in the context of effective field theory, a viable perturbative approach to calculating elementary processes is possible. Some non-perturbative approaches, most notably loop quantum gravity and combinatorial quantum gravity imply the existence of a minimal length. To circumvent the seeming contradiction between the existence of a minimum length and the principle of special relativity, Double Special Relativity introduces modified dispersion relationships that reconcile the conflict. In this work, we combine these dispersion relationships with an effective field theory approach to compute the first post Newtonian correction to the bending of light by a massive object. The calculation offers the prospect of a directly measurable effect that rests upon both the existence of a quantized gravitational field and a minimal length. Experimental verification would provide evidence of the existence of a quantum theory of gravity, and the fundamental quantization of spacetime with a bound on the minimal distance.

Lepton universality violation by Kaluza-Klein neutrinos in b → sll transition

Recent measure of RK, involving the decays of b→sl+l−, by the LHCb at CERN strengthened the deviation from the Standard Model prediction. The best fit in the updated global analysis suggests that the muon specific Wilson coefficients C9bsμμ=−C10bsμμ should be about −0.41. In this paper, we show that the accumulate effects of KK modes of a singlet Dirac neutrino propagating in the large extra-dimensional space naturally provide C9bsll=−C10bsll to explain the anomaly. By taking the muon Yukawa coupling to be about 5, the fundamental scale in the extra-dimensional framework should be lowered down to about 20 TeV if there are two additional spatial dimensions.

Investigating bounds on the extended uncertainty principle metric through astrophysical tests

In this paper, we consider the gravitational tests for the extended uncertainty principle (EUP) metric, which is a large-scale quantum correction to Schwarzschild metric. We calculate gravitational redshift, geodetic precession, Shapiro time delay, precession of Mercury and S2 star's orbits. Using the results of experiments and observations, we obtain the lower bounds for the EUP fundamental length scale . We obtain the smallest bound for gravitational redshift, and the largest bound for the precession of S2's orbit.

Polar vortex crystals: Emergence and structure

Vortex crystals are quasiregular arrays of like-signed vortices in solid-body rotation embedded within a uniform background of weaker vorticity. Vortex crystals are observed at the poles of Jupiter and in laboratory experiments with magnetized electron plasmas in axisymmetric geometries. We show that vortex crystals form from the free evolution of randomly excited two-dimensional turbulence on an idealized polar cap. Once formed, the crystals are long lived and survive until the end of the simulations (300 crystal-rotation periods). We identify a fundamental length scale, Lγ=(U/γ)1/3, characterizing the size of the crystal in terms of the mean-square velocity U of the fluid and the polar parameter γ=fp/a2p, with fp the Coriolis parameter at the pole and ap the polar radius of the planet.

From Eikonal to Antieikonal Approximations: Competition of Scales in the Framework of Schrödinger and Classical Wave Equation

Abstract We present a description of certain limits associated with the Schrödinger equation, the classical wave equation, and Maxwell equations. Such limits are mainly characterized by the competition of two fundamental scales. More precisely: (1) The competition of an exploratory wavelength and the scale of fluctuations is associated with the media where the propagation takes place. From that, the universal behaviors arise eikonal and anti-eikonal. (2) In the context above, it is specially relevant and promising the study of propagation of electromagnetic waves in a media with a self-similar structure, like a fractal one. These systems offer the suggestive scenario where the eikonal and anti-eikonal behaviors are simultaneous. This kind of study requires large and massive computations that are mainly possible in the framework of the cloud computing. Recently, we started to carry out this task. (3) Finally and as a collateral aspect, we analyze the Planck constant in the interval 0≤h≤∞.

Mutations of Omicron Variant at the Interface of the Receptor Domain Motif and Human Angiotensin-Converting Enzyme-2.

The most recent Omicron variant of SARS-CoV-2 has caused global concern and anxiety. The only thing certain about this strain, with a large number of mutations in the spike protein, is that it spreads quickly, seems to evade immune defense, and mitigates the benefits of existing vaccines. Based on the ultra-large-scale ab initio computational modeling of the receptor binding motif (RBM) and the human angiotensin-converting enzyme-2 (ACE2) interface, we provide the details of the effect of Omicron mutations at the fundamental atomic scale level. In-depth analysis anchored in the novel concept of amino acid-amino acid bond pair units (AABPU) indicates that mutations in the Omicron variant are connected with (i) significant changes in the shape and structure of AABPU components, together with (ii) significant increase in the positive partial charge, which facilitates the interaction with ACE2. We have identified changes in bonding due to mutations in the RBM. The calculated bond order, based on AABPU, reveals that the Omicron mutations increase the binding strength of RBM to ACE2. Our findings correlate with and are instrumental to explain the current observations and can contribute to the prediction of next potential new variant of concern.

A Guide to Realistic Uncertainties on the Fundamental Properties of Solar-type Exoplanet Host Stars

Abstract Our understanding of the properties and demographics of exoplanets critically relies on our ability to determine the fundamental properties of their host stars. The advent of Gaia and large spectroscopic surveys has now made it possible, in principle, to infer the properties of individual stars, including most exoplanet hosts, to very high precision. However, we show that, in practice, such analyses are limited by uncertainties in both the fundamental scale and our models of stellar evolution, even for stars similar to the Sun. For example, we show that current uncertainties on measured interferometric angular diameters and bolometric fluxes set a systematic uncertainty floor of ≈2.4% in temperature, ≈2.0% in luminosity, and ≈4.2% in radius. Comparisons between widely available model grids suggest uncertainties of order ≈5% in mass and ≈20% in age for main-sequence and subgiant stars. While the radius uncertainties are roughly constant over this range of stars, the model-dependent uncertainties are a complex function of luminosity, temperature, and metallicity. We provide open-source software for approximating these uncertainties for individual targets and discuss strategies for reducing these uncertainties in the future.

Non-trivial time crystal-like ground state for gravitational perturbation in quadratic gravity

We consider gravitational perturbation around maximally symmetric background of a theory of gravity involving quadratic curvature correction. This leads to a decoupled model of the standard transverse, traceless graviton mode and an additional scalar degree of freedom. Evolution of the latter is governed by a Lagrangian, which depends on higher derivative terms, inherited from the quadratic curvature correction in the action. It turns out that stability of the gravitational theory allows the scalar sector to choose between possible lowest energy states (or, ground states), that can sustain periodic form of inhomogeneity, either in space or in time. The latter, with a restricted form of invariance in time translation, is possibly a variant form of the time crystal. Existence of this novel ground state, depicting a time crystal, is solely related to the presence of higher curvature terms in the action. In particular, this non-trivial condensate-like ground state describe the spacetime fabric itself by introducing fundamental scales in the theory. Possible implications are also discussed.

Measurement properties of the Swedish clinical outcomes in routine evaluation outcome measures (CORE-OM): Rasch analysis and short version for depressed and anxious out-patients in a multicultural area

IntroductionThe Swedish version of the patient-reported Clinical Outcomes in Routine Evaluation Outcome Measures (CORE-OM) has demonstrated high reliability and acceptable convergent validity in explanatory factor analyses. However, the fundamental scale properties have not yet been validated according to item response theory. The aim of this study was to analyze the measurement properties of the Swedish CORE-OM in a cohort of psychiatric out-patients with depression and anxiety in a multicultural area and to explore combinations of items based on shorter versions of the scale (CORE-10, CORE-6D) to improve measurement properties.MethodsData from CORE-OM assessments of 337 patients were analyzed using Rasch analysis. The patients had a mean age of 30 ± 14 years, the majority were women (72%). Requirements for measurement properties were checked: overall model fit, item fit residuals, targeting, internal consistency, differential item functioning and thresholds. Sensitivity to change was also analyzed.ResultsThe CORE-OM showed high internal consistency (person separation index = 0.947) and adequate targeting, but there was overall model misfit (item trait interaction χ2 = 917.53, p < 0.001), indication of local dependency, and differential item functioning in 9 items. The risk items showed problems with disordered thresholds. The emotional component of the shorter CORE-6D showed the best fit for our sample. Adding 3 items to include depressive and trauma-related content resulted in a unidimensional 8-item set with acceptable reliability, model fit, targeting and sensitivity to change.ConclusionFor out-patients with diagnosed depression or anxiety in a multicultural area, the Swedish CORE-OM showed high internal consistency, but also validity problems. Based on the shorter CORE-6D version, a unidimensional 8-item set could be an alternative brief measure of psychological distress for this population, but further validity studies are required. Qualitative studies exploring the CORE-OM items in non-native speakers are also warranted.