Jason Aaron Pollack

I am a postdoctoral research fellow in Mark Van Raamsdonk's group at the University of British Columbia. My research is conducted at the intersection between quantum gravity and quantum information, with a focus on decoherence, holography, and emergent spacetime.

The bulk of my recent work has been devoted to applying our knowledge of the general structure of quantum-mechanical and quantum field theories to gain insights into quantum gravity and cosmology. By taking seriously the idea that the universe can be described, directly or holographically, as a quantum state in a Hilbert space, we can constrain the observations experienced by an observer within any such state and understand under what circumstances they see something that looks like a gravitational spacetime. One particularly promising approach has been to apply tools from the decoherence program, which describes how classical behavior can emerge from subsystems of pure quantum states, to the particular case where the quantum state in question is the universe as a whole. Another is to determine the implications of information-theoretic constraints that apply to all quantum-mechanical states for the classical geometries that some of them describe. I have recently applied these tools to investigate the structure of and natural observables in quantum gravity, to constrain classical holographic states and wormhole geometries, and to develop a general quantum-information-theoretic framework for state reduction given a limited or coarse-grained set of observables, which can be applied to identify emergent classical degrees of freedom.

From 2012-2017, I was a graduate student in the Caltech Particle Theory Group, in the Department of Physics. My advisor was Sean Carroll. I was previously an undergraduate at Princeton University, where I did my senior thesis research with Paul Steinhardt.

Publications

1. S.M. Carroll, S. Leichenauer, and J. Pollack, 2013, "A Consistent Effective Theory of Long-Wavelength Cosmological Perturbations," Phys. Rev. D 90, 023518 (2014); arXiv:1310.2920.
2. K.K. Boddy, S.M. Carroll, and J. Pollack, 2014, "De Sitter Space Without Dynamical Quantum Fluctuations," Found. Phys., 46, 702 (2016); arXiv:1405.0298.
3. J. Pollack, D.N. Spergel, and P.J. Steinhardt, 2015, "Supermassive Black Holes from Ultra-Strongly Self-Interacting Dark Matter," Astrophys. J. 804, 131 (2015); arXiv:1501.00017.
4. N. Bao, C. Cao, S.M. Carroll, A. Chatwin-Davies, N. Hunter-Jones, J. Pollack, and G.N. Remmen, 2015, "Consistency Conditions for an AdS/MERA Correspondence," Phys. Rev. D 91, 125036 (2015); arXiv:1504.06632.
5. K.K. Boddy, S.M. Carroll, and J. Pollack, 2015, "Why Boltzmann Brains Don't Fluctuate Into Existence From the De Sitter Vacuum," in K. Chamcham, J. Silk, J. Barrow, & S. Saunders (Eds.), The Philosophy of Cosmology (pp. 228-240), Cambridge University Press; arXiv:1505.02780.
6. N. Bao, J. Pollack, and G.N. Remmen, 2015, "Splitting Spacetime and Cloning Qubits: Linking No-Go Theorems across the ER=EPR Duality," Fortschr. Phys. 63, 705 (2015); arXiv:1506.08203.
7. A. Bartolotta, S.M. Carroll, S. Leichenauer, and J. Pollack, 2015, "The Bayesian Second Law of Thermodynamics," Phys. Rev. E 94, 022102 (2016); arXiv:1508.02421.
8. N. Bao, J. Pollack, and G.N. Remmen, 2015, "Wormhole and Entanglement (Non-)Detection in the ER=EPR Correspondence," JHEP, 2015, 126; arXiv:1509.05426.
9. N. Bao, J. Pollack, and G.N. Remmen, 2016, "Entanglement Conservation, ER=EPR, and a New Classical Area Theorem for Wormholes," JHEP, 2016, 48; arXiv:1604.08217.
10. N. Bao, A. Bouland, A. Chatwin-Davies, J. Pollack, and H. Yuen, 2016, "Rescuing Complementarity With Little Drama," JHEP, 2016, 26; arXiv:1607.05141.
11. K.K. Boddy, S.M. Carroll, and J. Pollack, 2016, "How Decoherence Affects the Probability of Slow-Roll Eternal Inflation," Phys. Rev. D 96, 023539 (2017); arXiv:1612.04894.
12. N. Bao, S.M. Carroll, A. Chatwin-Davies, J. Pollack, and G.N. Remmen, 2017, "Branches of the Black Hole Wave Function Need Not Contain Firewalls," Phys. Rev. D 97, 126014 (2018); arXiv:1712.04955.
13. J. Pollack and A. Singh, 2018, "Towards Space from Hilbert Space: Finding Lattice Structure in Finite-Dimensional Quantum Systems," Quantum Stud.: Math. Found 6, 181 (2019); arXiv:1801.10168.
14. A. Bartolotta, N. Yunger Halpern, and J. Pollack, 2018, "Entropic uncertainty relations for quantum information scrambling,", Commun. Physics 2, 92 (2019), : arXiv:1806.04147.
15. N. Bao, A. Chatwin-Davies, J. Pollack, and G.N. Remmen, 2018, "Traversable Wormholes as Quantum Channels: Exploring CFT Entanglement Structure and Channel Capacity in Holography," JHEP, 2018, 71; arXiv:1808.05963.
16. F.M. Haehl, E. Mintun, J. Pollack, A.J. Speranza, and M. Van Raamsdonk, 2019, "Nonlocal multi-trace sources and bulk entanglement in holographic conformal field theories," JHEP, 2019, 5; arXiv:1904.01584.
17. N. Bao, A. Chatwin-Davies, J. Pollack, and G.N. Remmen, 2019, "Towards a Bit Threads Derivation of Holographic Entanglement of Purification," JHEP, 2019, 152; arXiv:1905.04317.
18. O. Kabernik, J. Pollack, and A. Singh, 2019, “Quantum State Reduction: Generalized Bipartitions from Algebras of Observables,” Phys. Rev. A 101, 032303 (2020); arXiv:1909.12851.
19. N. Bao, A. Chatwin-Davies, J. Pollack, and G.N. Remmen, 2019, "Cosmological Decoherence from Thermal Gravitons," JHEP, submitted; arXiv:1911.10207.
20. J. Pollack, M. Rozali, J. Sully, and D. Wakeham, 2020, "Eigenstate Thermalization and Disorder Averaging in Gravity," Phys. Rev. Lett., accepted; arXiv:2002.02971.

Ph.D. Dissertation

• Constraints on Cosmology and Quantum Gravity from Quantum Mechanics and Quantum Field Theory, 2017 (advisor: Sean Carroll)

Undergraduate Work

•   Undergraduate Fall Junior Paper: Dynamical Selection of the Cosmological 'Constant' in the Cyclic Model, 2011 (advisor: Paul Steinhardt)
•   Undergraduate Spring Junior Paper: Parameter Estimation of Selected ACT Clusters from X-Ray and Radio Observations, 2012 (advisor: Lyman Page)
•   Undergraduate Senior Thesis: Supermassive Black Holes from Gravothermal Collapse of Fractional Self-Interacting Dark Matter Halos, 2012 (advisor: Paul Steinhardt)