Séminaire Doctoral / Seminar PhD |
| « Guiding the hunt for fifth forces with numerical simulations » |
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Hugo Lévy |
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Scalar-tensor theories are one of the most natural alternatives to general relativity (GR), where gravity is mediated by both a tensor field and a scalar field. Among the wide variety of scalar-tensor models proposed over the past decades, some are already ruled-out by lab experiments or astrophysical observations while others remain viable by means of screening mechanisms that dynamically suppress deviations from GR in classical fifth force searches. The hunt for such hypothetical scalar fields thus requires designing novel and intelligent experiments. Alas, this task is partly impeded by the difficulty to accurately model their effects in complex setups.
In this week's YMCA, we will go on a wild safari across the zoo of modified gravity theories, with a focus on a strange yet undetected animal: the chameleon field. To that end, I will introduce you to femtoscope — a Python numerical tool based on the finite element method for computing scalar fifth-forces in the presence of arbitrary sources. The novelty and most important feature of femtoscope is that it includes a careful treatment of asymptotic boundary conditions — that is when the behaviour of the field is only known infinitely far away from the sources — which is essential to obtain a physically-meaningful numerical approximation. |
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vendredi 28 avril 2023 - 16:00 Salle des séminaires Évry Schatzman, Institut d'Astrophysique |
| Page web du séminaire / Seminar's webpage |