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SUMMARY:Electronic Structure Reading Group: Connecting DFT with Green's fu
 nction methods through the effective action formalism
DTSTART:20250317T160000
DTEND:20250317T173000
DTSTAMP:20260410T152317Z
UID:d1a0f6ebe6b7fb246a8be9cc9cccc55d38392abc5fc00ade34d6d0dd
CATEGORIES:Conferences - Seminars
DESCRIPTION:Simone Cigagna\nBoth density functional theory (DFT) and Green
 's function (GF) methods aim to reproduce the electronic structure of mate
 rials without directly computing the many-body wavefunction\, instead focu
 sing on simpler quantities: the ground-state electron density and the one-
 particle Green's function. Although they share similarities\, the mathemat
 ical formalisms underlying DFT and GF methods are completely different. DF
 T is formulated within the framework of first quantization\, whereas GF me
 thods are rooted in quantum field theory. The effective action formalism\,
  based on Feynman's path-integral and the Legendre transformation\, offers
  a unified framework that can bridge this gap. By applying this technique 
 and strategically choosing which operator to couple with a constraining fi
 eld\, it is possible to derive key functionals\, such as the Kohn-Sham fun
 ctional of DFT or the Luttinger-Ward functional of many-body perturbation 
 theory.\n\nReferences:\n- Fukuda\, R.\, Kotani\, T.\, Suzuki\, Y.\, & Yoko
 jima\, S. (1994). Density Functional Theory through Legendre Transformatio
 n. In Progress of Theoretical Physics (Vol. 92\, Issue 4\, pp. 833–862).
  Oxford University Press (OUP). https://doi.org/10.1143/ptp/92.4.833\n- Ge
 orges\, A.\, Kotliar\, G.\, Krauth\, W.\, & Rozenberg\, M. J. (1996). Dyna
 mical mean-field theory of strongly correlated fermion systems and the lim
 it of infinite dimensions. In Reviews of Modern Physics (Vol. 68\, Issue 1
 \, pp. 13–125). American Physical Society (APS). https://doi.org/10.1103
 /revmodphys.68.13\n- Martin\, R. M.\, Reining\, L.\, & Ceperley\, D. M. (2
 016). Functionals in many-particle physics. In Interacting Electrons: Theo
 ry and Computational Approaches (pp. 169–192). chapter 8\, Cambridge: Ca
 mbridge University Press.\n\n\n---\nThe electronic structure reading group
  brings together researchers and students interested in mathematical aspec
 ts of electronic structure problems and adjacent topics\, including:\n\n	D
 ensity Functional Theory\n	Many-body Schrödinger equation for electrons\n
 	Born-Oppenheimer Molecular Dynamics\n	Numerical analysis and error contro
 l\n\nFor updates\, join the matrix chat room at #electronic-structure:epf
 l.ch (requires a GASPAR account).\n\nWebsite: https://matmat.org/reading
 group/
LOCATION:MA B1 524 https://plan.epfl.ch/?room==MA%20B1%20524
STATUS:CONFIRMED
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