They're not different codepoints, they're being rendered as mathematical markup by MathJax. This rendering includes using a LaTeX-esque font rather like Computer Modern.
Arxiv does this presumably because some papers have mathematical expressions in the titles and abstracts. For example https://arxiv.org/abs/2401.04991
Arxiv does this presumably because some papers have mathematical expressions in the titles and abstracts. For example https://arxiv.org/abs/2401.04991