All Outputs (4)

Quantum tunnelling, real-time dynamics and Picard-Lefschetz thimbles (2019)
Journal Article
Mou, Z.-G., Saffin, P. M., & Tranberg, A. (2019). Quantum tunnelling, real-time dynamics and Picard-Lefschetz thimbles. Journal of High Energy Physics, 2019(11), Article 135. https://doi.org/10.1007/jhep11%282019%29135

We follow up the work, where in light of the Picard-Lefschetz thimble approach, we split up the real-time path integral into two parts: the initial density matrix part which can be represented via an ensemble of initial conditions, and the dynamic pa... Read More about Quantum tunnelling, real-time dynamics and Picard-Lefschetz thimbles.

Real-time quantum dynamics, path integrals and the method of thimbles (2019)
Journal Article
Mou, Z.-G., Saffin, P. M., Tranberg, A., & Woodward, S. (2019). Real-time quantum dynamics, path integrals and the method of thimbles. Journal of High Energy Physics, 2019(6), Article 94. https://doi.org/10.1007/jhep06%282019%29094

Direct numerical evaluation of the real-time path integral has a well-known sign problem that makes convergence exponentially slow. One promising remedy is to use Picard-Lefschetz theory to flow the domain of the field variables into the complex plan... Read More about Real-time quantum dynamics, path integrals and the method of thimbles.

Well-tempered cosmology (2019)
Journal Article
Emond, W. T., Li, C., Saffin, P. M., & Zhou, S.-Y. (2019). Well-tempered cosmology. Journal of Cosmology and Astroparticle Physics, 2019(05), Article 038. https://doi.org/10.1088/1475-7516/2019/05/038

We examine an approach to cosmology, known as Well-Tempering, that allows for a de Sitter phase whose expansion is independent of the cosmological constant. Starting from a generic scalar-tensor theory compatible with the recent gravitational wave ob... Read More about Well-tempered cosmology.

Dark Energy after GW170817 Revisited (2019)
Journal Article
Copeland, E. J., Kopp, M., Padilla, A., Saffin, P. M., & Skordis, C. (2019). Dark Energy after GW170817 Revisited. Physical Review Letters, 122(6), Article 061301. https://doi.org/10.1103/physrevlett.122.061301

We revisit the status of scalar-tensor theories with applications to dark energy in the aftermath of the gravitational wave signal GW170817 and its optical counterpart GRB170817A. At the level of the cosmological background, we identify a class of th... Read More about Dark Energy after GW170817 Revisited.