Betting on Future Physics

Abstract

<jats:title>Abstract</jats:title> <jats:p>The ‘cosmological constant problem’ (CCP) has historically been understood as describing a conflict between cosmological observations in the framework of general relativity (GR) and theoretical predictions from quantum field theory (QFT), which a future theory of quantum gravity ought to resolve. I argue that this view of the CCP is best understood in terms of a bet about future physics made on the basis of particular interpretational choices in GR and QFT, respectively. Crucially, each of these choices must be taken as itself grounded in the sucesses of the respective theory for this bet to be justified.</jats:p> <jats:p>1 Introduction 2 The Cosmological Constant Problem 2.1 The physics that anticipates ‘vacuum energy’ 2.2 Getting to zero-point energies 2.3 Getting to the cosmological constant 3 The Epistemology of Physical Interpretation 4 The View from High-Energy Physics 5 Concluding Remarks</jats:p>

Λ and the Limits of Effective Field Theory

“…Schneider (2020Schneider ( , 2022 has argued that the problem takes different forms depending on one's interpretative stance toward QFT and GR, suggesting different strategies to (dis)solve the problem in quantum gravity. Here, we aim to give a clear formulation of the problem within the EFT framework.…”

Trans-Planckian philosophy of cosmology

“…These parallels suggest that there is nothing new, methodologically speaking, about something like trans-Planckian censorship coming to acquire a life of its own at the semiclassical frontiers of quantum gravity research, and to thereby shape ongoing research in the discipline. Moreover, at least in the case of the cosmological constant problem, I have argued in[Schneider, 2020b] that this state of affairs can be epistemically well founded.3 In a sense, the claim here is that a theorist's embrace of trans-Planckian censorship amounts to their adopting a working hypothesis, specifically within the context of quantum gravity research, about a lack of actual trans-Planckian physics within the early history of our universe (at least, as we typically understand that history, by means of positing an inflationary epoch). Note that this framing leaves open the possibility that our expectations about the future theory of quantum gravity could, presently, serve as impetus for revising our thinking about early universe structure formation in terms of inflationary dynamics.…”