# Quantum Raychaudhuri Equation: Implications for spacetime singularities and the quantum origin of Lambda

### APA

Das, S. (2020). Quantum Raychaudhuri Equation: Implications for spacetime singularities and the quantum origin of Lambda. Perimeter Institute. https://pirsa.org/20090002

### MLA

Das, Saurya. Quantum Raychaudhuri Equation: Implications for spacetime singularities and the quantum origin of Lambda. Perimeter Institute, Sep. 24, 2020, https://pirsa.org/20090002

### BibTex

@misc{ pirsa_PIRSA:20090002, doi = {10.48660/20090002}, url = {https://pirsa.org/20090002}, author = {Das, Saurya}, keywords = {Quantum Gravity}, language = {en}, title = {Quantum Raychaudhuri Equation: Implications for spacetime singularities and the quantum origin of Lambda}, publisher = {Perimeter Institute}, year = {2020}, month = {sep}, note = {PIRSA:20090002 see, \url{https://pirsa.org}} }

Saurya Das University of Lethbridge

## Abstract

The Raychaudhuri equation predicts the convergence of geodesics and gives rise to the singularity theorems. The quantum Raychaudhuri equation (QRE), on the other hand, shows that quantal trajectories, the quantum equivalent of the geodesics, do not converge and are not associated with any singularity theorems. Furthermore, the QRE gives rise to the quantum corrected Friedmann equation. The quantum correction is dependent on the wavefunction of the perfect fluid whose pressure and density enter the Friedmann equation. We show that for a suitable choice of the wavefunction this term can be interpreted as a small positive cosmological constant.