Charles COSNIER-HOREAU

PhD student

Research activities : String Theory

Thesis :

"BPS states and BPS amplitudes in string theory"
Advisors: Guillaume Bossard and Boris Pioline (LPTHE)
Phd Defense on 4th of september 2018

Research :

We study how perturbative and non-perturbative states in string theory can combine into specific functions called automorphic functions. These functions have the special property of living in a finite dimensional space. Their existence and the description they provide is thus very particular (this phenomenon already appears in some simpler but still mysterious models like the infamous Ising model).

The class of function that we study is related to protected couplings in string theory that appear in the low-energy limit of the supergravity effective action, such as gauge or gravitational couplings. The state counting provided by such functions can yield to the degeneracy of some types of extremal black holes, and hence give a statistical interpretation to the black hole entropy known since the work of Bekenstein and Hawking.

Publications :

Bossard G, Cosnier-Horeau C, Pioline B. 
Exact effective interactions and 1/4-BPS dyons in heterotic CHL orbifolds.
arxiv.org; hep-th/1806.03330

June 2018

Bossard G, Cosnier-Horeau C, Pioline B. 
Four-derivative couplings and BPS dyons in heterotic CHL orbifolds. 
Scipost Physics 2017;3(1):UNSP 008. 
DOI: 10.21468/SciPostPhys.3.1.008

Bossard G, Cosnier-Horeau C, Pioline B.
Protected couplings and BPS dyons in half-maximal supersymmetric string vacua.
Physics Letters B 2017;765:377–381.
doi:10.1016/j.physletb.2016.12.035

Address CPHT, Ecole Polytechnique, 91128 Palaiseau cedex, France
Phone number 01 69 33 42 63
Fax 01 69 33 49 49
Contact firstname.lastname@polytechnique.edu
Office Aile zéro, pièce 1028

 

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