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Quantum information and the C-theorem in de Sitter
by Nicolás Abate, Gonzalo Torroba
Submission summary
| Authors (as registered SciPost users): | Nicolás Abate |
| Submission information | |
|---|---|
| Preprint Link: | https://arxiv.org/abs/2409.18186v2 (pdf) |
| Date accepted: | 2024-12-19 |
| Date submitted: | 2024-12-09 13:36 |
| Submitted by: | Abate, Nicolás |
| Submitted to: | SciPost Physics |
| Ontological classification | |
|---|---|
| Academic field: | Physics |
| Specialties: |
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| Approach: | Theoretical |
Abstract
Information-theoretic methods have led to significant advances in nonperturbative quantum field theory in flat space. In this work, we show that these ideas can be generalized to field theories in a fixed de Sitter space. Focusing on 1+1-dimensional field theories, we derive a boosted strong subadditivity inequality in de Sitter, and show that it implies a C-theorem for renormalization group flows. Additionally, using the relative entropy, we establish a Lorentzian bound on the entanglement and thermal entropies for a field theory inside the static patch. Finally, we discuss possible connections with recent developments using unitarity methods.
Author indications on fulfilling journal expectations
- Provide a novel and synergetic link between different research areas.
- Open a new pathway in an existing or a new research direction, with clear potential for multi-pronged follow-up work
- Detail a groundbreaking theoretical/experimental/computational discovery
- Present a breakthrough on a previously-identified and long-standing research stumbling block
Author comments upon resubmission
List of changes
REPORT 1
1. We have added Footnote 4 to explain this point.
2. This is an important point, also raised by the other referee. We have added a new paragraph on this at the beginning of Sec. 3. We have explained this point below Eq. (3.8).
4. This point was also raised by the other referee. We have added a short distance cutoff to regularize the integral of eq. (3.11) and expanded on this below such equation.
5. In the evaluation of (5.24) we used the fact that the QFT modular hamiltonian is known to be the generator of static time evolution. This is a key simplification since for arbitrary regions the modular hamiltonian for the QFT is not local, and there does not exist a simple expression in terms of correlators for $\Delta C(\theta_0)$.
6. We agree that providing examples in free massive theories would be very useful. We are currently working on this project, which turns out to be nontrivial due to the de Sitter scale factor.
REPORT 2
Introduction
1.2.3. Added 3 new paragraphs to the introduction in order to address the questions in the referee report.
4. Replaced Lorentz invariance by Poincare invariance in the Introduction
5. Added refs. on the F-theorem in the Introduction.
Section 2
1. We explained below (2.23) why the extremum is a minimum.
Section 3
1. This is an important point and we agree that it requires more explanations. We have added a new paragraph on this at the beginning of Sec. 3.
2. We have expanded on this point below eq. (3.11).
3. We have clarified this point below. eq. (3.15).
We also note that we have fixed a typo in a factor of 2 in Eq. (4.10).
Current status:
Editorial decision:
For Journal SciPost Physics: Publish
(status: Editorial decision fixed and (if required) accepted by authors)