Thibaut COUDARCHET
PhD Student
Research group: String Theory
Thesis
"String theory: Supersymmetry breaking, moduli stabilization and cosmological considerations"
Advisor: Hervé Partouche
PhD Defense n Thursday 30th of September at 2pm at Ecole polytechnique in "Amphi Lagarrigue".
Research interests
String theory, supersymmetry breaking, moduli stabilization, cosmology.
Abstract
The purpose of this thesis is to explore various aspects of string theory, a unified theory of matter and all fundamental interactions including gravity. Some useful key ingredients of the theory and its construction are reviewed before investigating three theoretical facets of it. First, a new supersymmetrybreaking mechanism in openstring models is developed and its features are described, commented and put into perspective with other existing mechanisms. Second, oneloop masses acquired by treelevel moduli are studied in a type I string context with N=2 to N=0 breaking of supersymmetry implemented by a ScherkSchwarz mechanism. Different strategies are used to conclude on the stability or not at one loop of the wide variety of moduli present in the model, from Taylor expansion of the effective potential to the evaluation of genus1 twopoint correlation functions through arguments arising from the duality between the heterotic and type I string. Eventually, in heterotic string models, the backreaction of the oneloop potential generated by supersymmetry breaking on the cosmology is studied. Flat and everexpanding solutions are looked for in a cold setup while a new process for generating a darkmatter relic density is developed with implementation of finite temperature.
Publications
Coudarchet T, Dudas E, Partouche H.
Geometry of orientifold vacua and supersymmetry breaking.
Journal of High Energy Physics. 2021(7):104.
DOI: 10.1007/JHEP07(2021)104.
Abel S, Coudarchet T, Partouche H.
On the stability of openstring orbifold models with broken supersymmetry.
Nuclear Physics B. 2020;957:115100.
DOI: 10.1016/j.nuclphysb.2020.115100.
Coudarchet T, Heurtier L, Partouche H.
Spontaneous darkmatter mass generation along cosmological attractors in string theory.
Journal of High Energy Physics. 2019(3):117.
DOI: 10.1007/JHEP03(2019)117.
Coudarchet T, Heurtier L, Partouche H.
Spontaneous freeze out of dark matter. 2019 Corfu Summer Institute "School and Workshops on Elementary Particle Physics and Gravity", CORFU 2019, 31 August 2019  25 September 2019. Proceedings of Science, Volume 3762019, Article number 136.
Partouche H, Coudarchet T.
Moduli stability in type I string orbifold models.
2019 Corfu Summer Institute "School and Workshops on Elementary Particle Physics and Gravity", CORFU 2019, 31 August 2019  25 September 2019
Proceedings of Science, Volume 3762019, Article number 164.
Coudarchet T, Partouche H.
Quantum noscale regimes and moduli dynamics.
Nuclear Physics B. 2018;933:13484.
DOI: 10.1016/j.nuclphysb.
Coudarchet T, Fleming C, Partouche H.
Quantum noscale regimes in string theory.
Nuclear Physics B. 2018;930:23554.
DOI: 10.1016/j.nuclphysb.
Preprint
Coudarchet T, Partouche H.
Oneloop masses of NeumannDirichlet open strings and boundarychanging vertex operators.
arXiv:201113725
Coudarchet T, Partouche H.
Twopoint functions of NeumannDirichlet openstring sector moduli.
arXiv:201214442
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