SPACE seminar: Laura Antonia Cerbone ; Filippo Contino

Tuesday 16 Jun 2026, 12:00 → 13:00 Europe/Rome

Speaker 1: Laura Antonia Cerbone (SSM)

Title 1: Bone densitometry in space using Timepix3 detectors

Abstract 1: In this talk, the DXA4A project and the final design of the proposed compact bone densitometer for space applications will be presented. DXA4A aims to enable in-flight monitoring of astronauts’ bone health during long-duration missions, addressing the progressive bone loss associated with microgravity exposure.
The presentation will also include the first experimental results obtained with photon-counting Timepix3 detectors equipped with both silicon and CdTe sensors. Measurements performed on calibration phantoms and ex-vivo specimens demonstrate the feasibility of assessing areal bone mineral density using Timepix-based technology. These preliminary results support the potential of photon-counting detectors for compact, low-dose bone densitometry systems suitable for both spaceflight and terrestrial applications.

References 1:

1. Cerbone LA et al, Design of a Novel DXA Scanner with a CdTe Photon-Counting Timepix4 Detector for Peripheral Bone Densitometry, Appl. Sci. 2026, 16(12), 5745; https://doi.org/10.3390/app16125745
2. Gabel, L., Liphardt, A. M., Hulme, P. A., Heer, M., Zwart, S. R., Sibonga, J. D., Smith, S. M., & Boyd, S. K. (2022). Incomplete recovery of bone strength and trabecular microarchitecture at the distal tibia 1 year after return from long duration spaceflight. Scientific Reports, 12(1). https://doi.org/10.1038/s41598-022-13461-1
3. Stavnichuk, M., Mikolajewicz, N., Corlett, T., Morris, M., & Komarova, S. V. (2020). A systematic review and meta-analysis of bone loss in space travelers. npj Microgravity, 6(1), 13. https://doi.org/10.1038/s41526-020-0103-2

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Speaker 2: Filippo Contino (SSM)

Title 2: Vacuum stability in Geometric Trinity Gravity

Abstract 2: The decay of a metastable (false) vacuum is a crucial non-perturbative phenomenon, as it plays an important role in constraining Standard Model and beyond the Standard Model physics. In particular, it has been shown that gravity can have a significant impact on the calculation of the decay rate. In this context, it is natural to ask whether different but classically equivalent formulations of gravity lead to the same physical predictions. In this talk, I will discuss vacuum decay in General Relativity and in its teleparallel and symmetric teleparallel formulations, namely TEGR and STEGR. Although these theories describe the same classical dynamics, it is of paramount importance to understand whether this equivalence persists also at the quantum level. In this respect, the analysis of vacuum stability may provide a particularly sensitive testing ground. The central question addressed in my talk is whether the decay rate of a false vacuum computed within TEGR or STEGR coincides with the corresponding result obtained in GR. I will show that the tunneling exponent remains unchanged, offering a non-trivial example in which the equivalence between different formulations of gravity extends beyond classical dynamics.

References 2:

1. Impact of New Physics on the EW vacuum stability in a curved spacetime background - E. Bentivegna, V. Branchina, F. Contino, D. Zappal`a, JHEP 1712 (2017) 100;
2. Protecting the stability of the electroweak vacuum from Planck-scale gravitational effects - V. Branchina, F. Contino, A. Pilaftsis, Phys.Rev.D 98 (2018) 7, 075001;
3. Direct Higgs-gravity interaction and stability of our Universe - V. Branchina, E. Bentivegna, F. Contino, D. Zappal`a, Phys.Rev.D 99 (2019) 9, 096029;

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