Massive scalar field near a cosmic string

The $\zeta$ function of a massive scalar field near a cosmic string is computed and then employed to find the vacuum fluctuation of the field. The vacuum expectation value of the energy-momentum tensor is also computed using a point-splitting approach. The obtained results could be useful also for the case of self-interacting scalar fields and for the finite-temperature Rindler space theory.Comment: 15 pages, standard LaTeX, no figures. Reference [14] correcte

Thermal partition function of photons and gravitons in a Rindler wedge

The thermal partition function of photons in any covariant gauge and gravitons in the harmonic gauge, propagating in a Rindler wedge, are computed using a local $\zeta$-function regularization approach. The correct Planckian leading order temperature dependence $T^4$ is obtained in both cases. For the photons, the existence of a surface term giving a negative contribution to the entropy is confirmed, as earlier obtained by Kabat, but this term is shown to be gauge dependent in the four-dimensional case and, therefore is discarded. It is argued that similar terms could appear dealing with any integer spin $s\geq 1$ in the massless case and in more general manifolds. Our conjecture is checked in the case of a graviton in the harmonic gauge, where different surface terms also appear, and physically consistent results arise dropping these terms. The results are discussed in relation to the quantum corrections to the black hole entropy.Comment: 29 pages, RevTeX, no figures. Minor errors corrected and a few comments changed since first submission. To be published on Phys.Rev.

Metabolic and Functional Profile of Premenopausal Women With Metabolic Syndrome After Training With Elastics as Compared to Free Weights

The aim of this study was to compare the effects of a strength training program (STP) using free weights (FW) versus elastic tubing (ET) in 62 premenopausal, sedentary women diagnosed with metabolic syndrome (MS). Participants were randomly assigned to the FW or ET experimental group (EG) or a control group whose members remained sedentary. Members of each EG followed their assigned STP for 12 weeks, and biomarkers (BMs) related to MS and motor function (MF) parameters were evaluated. Both EGs showed a significant reduction in C-reactive protein level and a positive trend in the other BMs. Almost all MF parameters increased significantly in both EGs. No positive changes were found in the CG. These results indicate that the implementation of an STP, with either FW or ET, improves both metabolic health and MF and should be considered part of the basic approach to health care in women

Revisiting Evaluation Metrics for Semantic Segmentation: Optimization and Evaluation of Fine-grained Intersection over Union

Semantic segmentation datasets often exhibit two types of imbalance: \textit{class imbalance}, where some classes appear more frequently than others and \textit{size imbalance}, where some objects occupy more pixels than others. This causes traditional evaluation metrics to be biased towards \textit{majority classes} (e.g. overall pixel-wise accuracy) and \textit{large objects} (e.g. mean pixel-wise accuracy and per-dataset mean intersection over union). To address these shortcomings, we propose the use of fine-grained mIoUs along with corresponding worst-case metrics, thereby offering a more holistic evaluation of segmentation techniques. These fine-grained metrics offer less bias towards large objects, richer statistical information, and valuable insights into model and dataset auditing. Furthermore, we undertake an extensive benchmark study, where we train and evaluate 15 modern neural networks with the proposed metrics on 12 diverse natural and aerial segmentation datasets. Our benchmark study highlights the necessity of not basing evaluations on a single metric and confirms that fine-grained mIoUs reduce the bias towards large objects. Moreover, we identify the crucial role played by architecture designs and loss functions, which lead to best practices in optimizing fine-grained metrics. The code is available at \href{https://github.com/zifuwanggg/JDTLosses}{https://github.com/zifuwanggg/JDTLosses}.Comment: NeurIPS 202

Via-SEES: Variability in Atmosphere from Solar Energetic Electrons

Variability In Atmosphere from Solar Energetic Electron Study (VIA-SEES) is a hybrid science mission and technology development campaign from the Earth and Planetary Exploration Technologies (EPET) program at the University of Hawai’i. It is oriented around establishing a direct correlation between Solar Radiation Events (SREs) and Variability in Atmospheric gases, specifically Nitric and Nitrous Oxide, as well as Ozone. The mission is intended to fly on a 3U CubeSat and will collect a data set which is multimodal. To achieve robust performance, a variety of techniques are employed to make the science data set easier to interpret by an analyst. It is important to consider the format of the data sets, which is generally given by the instrument collecting the data. To allow for a better establishment of an anticoincidence, meaning that there is a precise correlation between 2 readings on the same index, a systems engineering approach is taken. This is as the science mission requirements should drive the design of the mission. A comprehensive approach is taken in the design of the VIA-SEES spacecraft, to maximize the scientific value of the mission

Role of causality in ensuring unconditional security of relativistic quantum cryptography

The problem of unconditional security of quantum cryptography (i.e. the security which is guaranteed by the fundamental laws of nature rather than by technical limitations) is one of the central points in quantum information theory. We propose a relativistic quantum cryptosystem and prove its unconditional security against any eavesdropping attempts. Relativistic causality arguments allow to demonstrate the security of the system in a simple way. Since the proposed protocol does not employ collective measurements and quantum codes, the cryptosystem can be experimentally realized with the present state-of-art in fiber optics technologies. The proposed cryptosystem employs only the individual measurements and classical codes and, in addition, the key distribution problem allows to postpone the choice of the state encoding scheme until after the states are already received instead of choosing it before sending the states into the communication channel (i.e. to employ a sort of ``antedate'' coding).Comment: 9 page

Competing mechanisms for singlet-triplet transition in artificial molecules

We study the magnetic field induced singlet/triplet transition for two electrons in vertically coupled quantum dots by exact diagonalization of the Coulomb interaction. We identify the different mechanisms occurring in the transition, involving either in-plane correlations or localization in opposite dots, depending on the field direction. Therefore, both spin and orbital degrees of freedom can be manipulated by field strength and direction. The phase diagram of realistic devices is determined.Comment: To appear in Phys. Rev. B - Rapid Comm. - 5 pages, 3 figure

A Bimodal Science Measurements for Earth Remote Sensing on a 3U CubeSat Platform

Solar energetic events, which include solar flares and solar mass ejections affect the Earth\u27s atmosphere. While solar energetic events have been observed to influence the chemistry of the mesospheric ozone, a comprehensive collection of quantitative data detailing the frequency, energy, and intensity of these interactions with the mesosphere have, to our knowledge, not before been collected. High-energy charged particles from solar energetic events can ionize molecules found within the mesosphere, accelerating the formation rate of reactive hydrogen atoms and nitrogen oxides. This results in reactions that catalyze the conversion of ozone back into diatomic oxygen. The Variability in Atmosphere – Solar Energetic Event study (VIA-SEEs) mission intends to utilize a 3U-CubeSat in Low Earth Orbit (LEO) to establish a singular data set for the purpose of understanding the correlation between flux in solar energetic events and variability in total reactive nitrogen oxides (NOy) and ozone (O3) concentrations in the mesosphere. This mission intends to produce a unique data set using a bimodal measurement scheme involving two instruments – one Variability in Atmosphere (VIA) commercial-off-the-shelf spectrophotometer for measuring NOy and O3 concentrations, and one in-house designed and fabricated solid-state radiation detector for observing the energy and flux of solar energetic electrons and protons

Anisotropic diffusion of water molecules in hydroxyapatite nanopores

Funded by EPSRC Grant EP/K000128/1