Quantum field theory

Conduct postdoctoral research in high-energy theory at Harvard. Areas include particle physics and astrophysics, quantum field theory, gravity and string theory; the expected start is September 2027.

Explore path-integration techniques linking quantum mechanics, quantum field theory and gravity. Five themes connect worldline methods, strong external backgrounds, heat-kernel expansions and resurgence, on-shell quantities, and geometry in first quantisation. Discussion includes curved spaces, superspace and nontrivial topology, as well as representations of wavefunctions, scattering amplitudes and gravitational waveforms. Review lectures introduce challenges in each area, followed by invited and contributed talks, two poster sessions and extended collaborative discussions across research com

Poisson sigma models connect geometric deformation with quantum field theory. This talk extends them into higher-dimensional theories with holomorphic and topological directions and relates the construction to quantization of factorization algebras. It develops interfaces, boundaries and defects, then uses Koszul duality to connect the models with quantum-group structures, including examples involving Lie bialgebras, W-algebras and Yangians.

Summing over spin structures in quantum field theory can be obstructed by a mod-16 anomaly extending the familiar fermion-parity anomaly. This talk uses homotopy theory and cobordism-group cohomology to explain the obstruction, its consequences for operations such as the GSO projection and dualities, and extensions involving other dimensions, symmetries and symmetry topological field theories.

Christian Ferko reviews correspondences between neural networks, quantum mechanics and quantum field theory. Wide networks behave like Gaussian processes and share features with free or weakly interacting fields. Focusing on one-dimensional field theories gives enough control to show, under mild assumptions, that any quantum-particle model has a neural-network representation. Architectural choices that satisfy quantum axioms then produce properties such as uncertainty relations. The presentation draws on joint work with Jim Halverson.