How to make a Universe (2502.00081v1)

Abstract: We establish the general conditions under which evolution in the laws of physics and matter creation or destruction are closely intertwined. They make use of global time variables canonically dual to the constants of Nature. Such times flow at a rate determined by what can be interpret as the chemical potential of the fundamental constants (in analogy with phenomenological clocks based on isentropic fluids). The general condition for violations of energy conservation is then that a matter parameter evolves as a function of a gravity clock or vice-versa. This framework can be envisaged as the environment within which a natural selection scenario operates, powered by random mutations in the values of the constants of nature (or indeed any other variability in the laws in terms of the times defined above). The prize function is the creation of matter, followed by its preservation. This can be accomplished in an environment where diffeomorphism invariance is among the possible theories, with mutations modelled, for example, on the absorbing Markov chain. In such a set-up the diffeormorphism invariant state with fixed constants (or any nearby state) should be the absorbing state. John Wheeler's ``higgledy-piggledy'' chaotic cosmic start therefore finds a realization in this model, where its own demise and the establishment of order and seemingly immutable laws is also a predection of the model.

• The paper proposes that evolving physical constants drive cosmic matter creation by linking time to the chemical potential of these constants.
• The authors employ a Hamiltonian formalism that separates global and local variables to model energy conservation violations.
• An absorbing Markov chain model illustrates the transition from chaotic cosmic states to fixed physical laws, hinting at a process of cosmic natural selection.

Overview of "How to make a Universe" by P. M. Bassani and J. Magueijo

The paper "How to make a Universe" by Bassani and Magueijo explores a theoretical framework that intertwines the evolution of the laws of physics with the dynamics of matter creation and destruction. The authors propose that the constants of nature and time are canonically dual, leading to a scenario where the variation in these constants over time embodies evolutionary changes in physics laws, consequently influencing energy conservation violations.

Framework and Key Concepts

The authors introduce a novel approach to understanding cosmic evolution by associating time with the "chemical potential" of fundamental constants. This analogy extends from phenomenological clocks based on isentropic fluids, wherein time is defined by the rate at which these constants change, akin to chemical reactions or non-adiabatic processes.

Central to their framework is the separation of global and local variables, framed in a Hamiltonian formalism. Global variables, which may include constants like the cosmological constant, are treated akin to conserved quantities in thermodynamics. The canonical formulation of these variables informs their evolution, drawing parallels between fundamental physics constants and thermodynamic Lagrange multipliers.

Matter Creation and Evolutionary Mechanism

The authors postulate that evolutionary scenarios within this framework can lead to matter production. They describe a condition wherein the variability in physics laws leads to energy conservation violations, quantified by a deterministic formula. This link between matter creation and the evolution of laws is reminiscent of a natural selection process, where successful variations "survive" by accruing or preserving matter.

Absorbing Markov Chain Model

To introduce randomness into this deterministic framework, Bassani and Magueijo propose an absorbing Markov chain model. This model represents different stages of cosmic evolution, with a focus on transitioning from a stochastic to a deterministic universe. The absorbing states represent fixed laws of physics, underlining that the universe we observe might be a result of a cessation of random mutations in cosmic laws.

The Markov model seeks to explain how a universe can transition from a chaotic "higgledy-piggledy" phase to one characterized by order and relatively immutable laws. The authors speculate that diffeomorphism invariance—a fundamental symmetry of general relativity—arises naturally as an "absorbing state," explaining why such symmetries dominate our universe's structure.

Implications and Future Directions

The implications of the paper are profound, suggesting that cosmic natural selection could underpin the emergence of ordered laws and matter in the universe. This theoretical construct not only aligns with philosophical notions that chaos precedes order but also provides a mathematical structure to explore such ideas within physics.

Speculatively, this framework could influence our understanding of dark matter, baryogenesis, and the constants of nature. The model's potential predictions for residual variability in these constants could spur future experimental inquiries.

Conclusion

Bassani and Magueijo's paper presents a thought-provoking perspective on cosmogenesis, blending philosophical ideas with robust mathematical modeling. By leveraging concepts from thermodynamics, Hamiltonian mechanics, and statistical physics, they offer a novel lens through which to explore the universe's evolution. The integration of deterministic and stochastic elements in cosmic development highlights a nuanced view of time and order, setting a foundation for future theoretical and observational investigations in cosmology.