APCTP	■ Introduction · Greetings · Milestones · Organization Chart · Board Members · Staff Members · Former Board Members · Annual Reports · APCTP Logo · Contact us ■ Members · Member Countries · Partnership Institutions ■ Media · APCTP in Media · AAPPS Bulletin ■ Visitor Information · Plan Your Visit · Directions · Tips for Visitors · Facilities Guide · Map ■ Sponsors

Activities	■ Scientific Activities · Scientific Programs · Seminars & Lectures · ICTP Affiliated Center (ICAC) · Scientific Calendar · Call for Programs · Past Scientific Programs · Past Seminars & Lectures · Payment ■ Awards and Visitors · Benjamin Lee Professorship · Visitors · Visitor Information · Visitor Application ■ Outreach Programs · Web Journal <Crossroads> · APCTP Books · Events · Science at Pohang · Past Events

Research	■ Junior Research Groups ■ Young Scientist Training Program ■ Senior Advisory Group ■ APCTP-POSTECH Fellows ■ Publications

Asia Pacific Network	■ Academic Activities in the AP Region · Seminars at IBS: Theoretical Physics of Complex Systems · Center For QUANTUM SPACETIME · Association of Asia Pacific Physical Societies · FIST - Asia Network on HEP · ANPhA - Asian Nuclear Physics Association · APCTP Japan Committee · ICTP Asian Network on Condensed Matter and Complex Systems

Seminars & Lectures

* TITLE

Multipoint correlation functions: spectral representation and numerical evaluation

* SPEAKERS

Name	Affiliation	E-mail
Seung-Sup Lee	Ludwig Maximilian University of Munich	s.lee(at)lmu.de

* HOST(Applicant)

Name	Affiliation	E-mail
Imtak Jeon	APCTP

* DATE / TIME

2021-03-29, 16:00

* LINK

https://zoom.us/meeting/register/tJ0tc-iprzgsG9TAsZFy8Wf45_ny9cOhB5QC

* ABSTRACT

Four-point correlation functions on the real-frequency axis describe experimentally relevant properties, such as nonlocal susceptibilities, transport, and inelastic photon scattering, of the systems of interacting quantum particles. However, the non-perturbative computation of real-frequency multipoint functions has been intractable. In this talk, I will summarize our recently developed method for non-perturbatively computing multipoint functions and its applications [1, 2]. We have derived generalized spectral representations for multipoint functions that apply in all of the commonly used many-body frameworks [1]: the imaginary-frequency Matsubara and the real-frequency zero-temperature and Keldysh formalisms. We have developed a numerical renormalization group (NRG) method for evaluating the spectral representations for local multipoint functions, which can treat temperatures and frequencies---imaginary or real---of all magnitudes, from large to arbitrarily small ones [2]. I will present the numerical results of four-point vertex functions and resonant inelastic x-ray scattering (RIXS) spectra of quantum impurity systems.

[1] F. B. Kugler*, S.-S. B. Lee*, and J. von Delft, arXiv:2101.00707.
*: These authors contributed equally to this work.
[2] S.-S. B. Lee, F. B. Kugler, and J. von Delft, arXiv:2101.00708.

* POSTER IMAGE

Map

How to get to APCTP

Scientific Activities Calendar

Scientific programs

Modal title

Modal title