arXiv subjects

Jason Alexander

Publications and source records attributed to Jason Alexander.

3 recordsLinked to original sources

arXiv2024

The Frequency and Mass-Ratio Distribution of Binaries in Clusters -- III: Probabilistic Generative Modelling of Six Young Open Clusters

We apply probabilistic generative modelling of colour-magnitude diagrams to six young Galactic open star clusters and determine their mass functions, binary mass-ratio distributions, and the frequencies of binary stars. We find that younger clusters tend to exhibit a higher incidence of binaries than their older counterparts. The mass-ratio distribution is fairly flat for the clusters with one exception that exhibits a sharp increase for $q\gtrsim0.9$. The ratio of the number of cluster binaries for which $q>0.75$ to the number of binaries for which $q>0.5$ (referred to as $FQ_{75}$) ranges from $\sim0.4 - 0.8$. This metric increases with the binary-star frequency of a cluster, but declines with cluster age. This may be due to non-ionizing 3-body dynamical processing of a primordial population of close binaries with initial mass ratios, $q \simeq 1$.

astro-ph.GA↗

arXiv2024

Can GPT-4 Models Detect Misleading Visualizations?

The proliferation of misleading visualizations online, particularly during critical events like public health crises and elections, poses a significant risk. This study investigates the capability of GPT-4 models (4V, 4o, and 4o mini) to detect misleading visualizations. Utilizing a dataset of tweet-visualization pairs containing various visual misleaders, we test these models under four experimental conditions with different levels of guidance. We show that GPT-4 models can detect misleading visualizations with moderate accuracy without prior training (naive zero-shot) and that performance notably improves when provided with definitions of misleaders (guided zero-shot). However, a single prompt engineering technique does not yield the best results for all misleader types. Specifically, providing the models with misleader definitions and examples (guided few-shot) proves more effective for reasoning misleaders, while guided zero-shot performs better for design misleaders. This study underscores the feasibility of using large vision-language models to detect visual misinformation and the importance of prompt engineering for optimized detection accuracy.

cs.CV↗

arXiv2011

Bose-Einstein condensation transition studies for atoms confined in Laguerre-Gaussian laser modes

Multiply-connected traps for cold, neutral atoms fix vortex cores of quantum gases. Laguerre-Gaussian laser modes are ideal for such traps due to their phase stability. We report theoretical calculations of the Bose-Einstein condensation transition properties and thermal characteristics of neutral atoms trapped in multiply connected geometries formed by Laguerre-Gaussian LG{p}{l} beams. Specifically, we consider atoms confined to the anti-node of a LG{0}{1} laser mode detuned to the red of an atomic resonance frequency, and those confined in the node of a blue-detuned LG{1}{1} beam. We compare the results of using the full potential to those approximating the potential minimum with a simple harmonic oscillator potential. We find that deviations between calculations of the full potential and the simple harmonic oscillator can be up to 3%-8% for trap parameters consistent with typical experiments.

physics.atom-ph↗