Triangle Seminars
Tuesday, 22 Oct 2019
TBA
Bernd Braunecker
(St. Andrews)
Wednesday, 23 Oct 2019
Differential equations for one-loop string integrals
📍 London
Oliver Schlotterer
(Uppsala)
Abstract:
In this talk, I will describe new mathematical structures in the low-energy
expansion of one-loop string amplitudes. The insertion of external states
on the open- and closed-string worldsheets requires integration over punctures
on a cylinder boundary and a torus, respectively. Suitable bases of such
integrals will be shown to obey simple first-order differential equations in the
modular parameter of the surface. These differential equations will be exploited
to perform the integrals order by order in the inverse string tension, similar
to modern strategies for dimensionally regulated Feynman integrals. Our
method manifests the appearance of iterated integrals over holomorphic
Eisenstein series in the low-energy expansion. Moreover, infinite families
of Laplace equations can be generated for the modular forms in closed-string
low-energy expansions.
In this talk, I will describe new mathematical structures in the low-energy
expansion of one-loop string amplitudes. The insertion of external states
on the open- and closed-string worldsheets requires integration over punctures
on a cylinder boundary and a torus, respectively. Suitable bases of such
integrals will be shown to obey simple first-order differential equations in the
modular parameter of the surface. These differential equations will be exploited
to perform the integrals order by order in the inverse string tension, similar
to modern strategies for dimensionally regulated Feynman integrals. Our
method manifests the appearance of iterated integrals over holomorphic
Eisenstein series in the low-energy expansion. Moreover, infinite families
of Laplace equations can be generated for the modular forms in closed-string
low-energy expansions.
Posted by: KCL
TBA
Fischbacher Thomas
(Google Research)
Anomalous supersymmetry
Kostas Skenderis
(University of Southampton)
Abstract:
I will present an introduction to anomalies and then discuss the recently discovered anomalies for supersymmetry.
I will present an introduction to anomalies and then discuss the recently discovered anomalies for supersymmetry.
Posted by: QMW
Thursday, 24 Oct 2019
Differential equations for one-loop string integrals
Oliver Schlotterer
(Uppsala University)
Abstract:
In this talk, I will describe new mathematical structures in the low-energy expansion of one-loop string amplitudes. The insertion of external states on the open- and closed-string worldsheets requires integration over punctures on a cylinder boundary and a torus, respectively. Suitable bases of such integrals will be shown to obey simple first-order differential equations in the modular parameter of the surface. These differential equations will be exploited to perform the integrals order by order in the inverse string tension, similar to modern strategies for dimensionally regulated Feynman integrals. Our method manifests the appearance of iterated integrals over holomorphic Eisenstein series in the low-energy expansion. Moreover, infinite families of Laplace equations can be generated for the modular forms in closed-string low-energy expansions.
In this talk, I will describe new mathematical structures in the low-energy expansion of one-loop string amplitudes. The insertion of external states on the open- and closed-string worldsheets requires integration over punctures on a cylinder boundary and a torus, respectively. Suitable bases of such integrals will be shown to obey simple first-order differential equations in the modular parameter of the surface. These differential equations will be exploited to perform the integrals order by order in the inverse string tension, similar to modern strategies for dimensionally regulated Feynman integrals. Our method manifests the appearance of iterated integrals over holomorphic Eisenstein series in the low-energy expansion. Moreover, infinite families of Laplace equations can be generated for the modular forms in closed-string low-energy expansions.
Posted by: QMW