Path summation offers a flexible general approach to quantum theory, including quantum gravity. In the latter setting, summation is performed over a space of evolutionary pathways in a history configuration space. Discrete causal histories called acyclic directed sets offer certain advantages over similar models appearing in the literature, such as causal sets. Path summation defined in terms of these histories enables derivation of discrete Schrödinger-type equations describing quantum spacetime dynamics for any suitable choice of algebraic quantities associated with each evolutionary pathway. These quantities, called phases, collectively define a phase map from the space of evolutionary pathways to a target object, such as the unit circle S 1 ⊂ C , or an analogue such as S 3 or S 7 . This paper explores the problem of identifying suitable phase maps for discrete quantum gravity, focusing on a class of S 1 -valued maps defined in terms of “structural increments” of histories, called terminal states. Invariants such as state automorphism groups determine multiplicities of states, and induce families of natural entropy functions. A phase map defined in terms of such a function is called an entropic phase map. The associated dynamical law may be viewed as an abstract combination of Schrödinger’s equation and the second law of thermodynamics.
Path summation offers a flexible general approach to quantum theory, including quantum gravity. In the latter setting, summation is performed over a space of evolutionary pathways in a history configuration space. Discrete causal histories called acyclic directed sets offer certain advantages over similar models appearing in the literature, such as causal sets. Path summation defined in terms of these histories enables derivation of discrete Schrödinger-type equations describing quantum spacetime dynamics for any suitable choice of algebraic quantities associated with each evolutionary pathway. These quantities, called phases, collectively define a phase map from the space of evolutionary pathways to a target object, such as the unit circle S 1 ⊂ C , or an analogue such as S 3 or S 7 . This paper explores the problem of identifying suitable phase maps for discrete quantum gravity, focusing on a class of S 1 -valued maps defined in terms of “structural increments” of histories, called terminal states. Invariants such as state automorphism groups determine multiplicities of states, and induce families of natural entropy functions. A phase map defined in terms of such a function is called an entropic phase map. The associated dynamical law may be viewed as an abstract combination of Schrödinger’s equation and the second law of thermodynamics.
This article presents a simplified version of the author's previous work. We first construct a causal growth process (CGP). We then form path Hilbert spaces using paths of varying lengths in the CGP. A sequence of positive operators on these Hilbert spaces that satisfy certain normalization and consistency conditions is called a quantum sequential growth process (QSGP). The operators of a QSGP are employed to define natural decoherence functionals and quantum measures. These quantum measures are extended to a single quantum measure defined on a suitable collection of subsets of a space of all paths. Continuing our general formalism, we define curvature operators and a discrete analogue of Einstein's field equations on the Hilbert space of causal sets. We next present a method for constructing a QSGP using an amplitude process (AP). We then consider a specific AP that employs a discrete analogue of a quantum action. Finally, we consider the special case in which the QSGP is classical. It is pointed out that this formalism not only gives a discrete version of general relativity, there is also emerging a discrete analogue of quantum field theory. We therefore have discrete versions of these two theories within one unifying framework.
The Causal Set hypothesis for Quantum Gravity asserts that the smooth Lorentzian spacetime manifold of General Relativity is only an approximation to a fundamental microscopic discrete structure: a locally-finite partially-ordered set. The points of this set are akin to the point-events of the spacetime manifold, and the order-relations among these points are akin to the causal-relations among these point-events. The local-finiteness condition implies a fundamental discreteness and provides an important [conformal] factor needed for the continuum approximations. In this dissertation, we address two aspects toward the formulation of a quantum dynamics for causal sets. The first aspect concerns the dynamics of a zero-mass classical scalar field on a background causal set, Poisson-sampled from an Alexandrov interval in (1 + 1)-dimensional Minkowski spacetime. Our numerical simulations suggest that actions can be defined for such a scalar field, expressed solely in terms of the causal set and the scalar field, which approximates the corresponding classical action on the continuum Minkowski spacetime. This result may help us describe matter and gauge fields in a local and Lorentz-invariant way on a causal set, a discrete structure now being considered as the arena for spacetime physics. More importantly, it may help us formulate an action for the causal set itself, which would be used in a sum-over-histories approach to describe the quantum dynamics of causal sets. The second aspect concerns Quantum Measure Theory, a new approach to quantum dynamics inspired by the sum-over-histories approach, which is better suited to formulating the dynamics of causal sets and of other alternative structures for spacetime. To better understand the mathematical structure underlying this new approach, we derive some algebraic identities involving the sum-rules of the Quantum Measure and its generalizations. We conclude with a discussion on possible applications and open problems concerning these aspects.
Discrete maps play an important role in the investigation \nof dynamical features of complex classical systems, especially \nwithin the theory of chaos. Similarly, quantum maps have proven \nto be a very useful mathematical tool within the study of complex \nquantum dynamical systems. Using the decoherent histories formulation \nof quantum mechanics we consider a particular framework for studying \nquantum maps which is motivated by the method of classical symbolic \ndynamics. Symbolic dynamics is known to be a very powerful method \nspecifically invented for the purpose of representing classical dynamical \nsystems by a discrete model that is suitable for information theoretic studies. \nOur framework uses the decoherent histories formalism which, \nsimilarly to classical symbolic dynamics, allows one to introduce information \ntheoretic quantities with respect to system dynamics. \nOur research within this framework can be viewed as a contribution \ntowards the development of a general theory of "quantum \nsymbolic dynamics". \n\nWe start by considering a special but very important example \nfor a quantum map: the quantum baker's map, invented for \nthe theoretical investigation of quantum chaos. \nHere we use the decoherent histories formalism to examine \nthe coarse-grained evolution of this map \nwith regard to the question of how classical predictability of \nthe evolution depends on the character of coarse-graining. \n%is affected by the choice of coarse-graining. \nWe demonstrate that hierarchical coarse-grainings display \ninteresting features with respect to this question. \n\nWe proceed with the investigation of decoherence properties \nof arbitrary unitary quantum maps. A number of interesting results \nis obtained within the framework of arbitrarily long histories \nconstructed from a fixed projective partition of a finite \ndimensional Hilbert space. In particular, we derive simple \nnecessary decoherence conditions, which employ only a single \niteration of a given unitary quantum map. Furthermore, \na surprising result is obtained with regard to the \nfundamental question of how the choice of the \ninitial state affects decoherence of histories. \nWithin the considered framework we show that if decoherence \nis established for arbitrary history lengths and all initial \nstates from the smallest natural set of states that \ncan be associated with the framework, then we get decoherence \nof such histories for arbitrary initial states. \nFinally, we make first steps towards proving analogous\nresults for approximate decoherence and suggest \nvarious questions for future research.\n
This paper introduces the Total Entropic Quantity (TEQ) framework, a structural reformulation of quantum theory grounded in two foundational axioms. Axiom 0 posits entropy as a generative constraint: a geometric principle that determines which configurations can stably distinguish themselves, independent of space, time, or dynamics. Here, entropy is defined as a curvature-functional over distinguishability configurations, preserving only those patterns that remain stable under finite informational resolution---that is, structures not dissolved by coarse-graining or limited observability. Axiom 1, the Minimal Principle (MP), selects from these structures those that are maximally stable under entropy-weighted variation. From this entropic foundation, core elements of quantum theory---including the Born rule, quantization, and Schrödinger dynamics---emerge as special cases of entropy-stabilized geometry. The framework derives an entropy-weighted path integral and introduces a corrected Schrödinger equation that governs evolution in regimes of finite entropy curvature. In the high-resolution limit (β→∞), TEQ reduces to standard unitary quantum mechanics; in more general regimes, entropy flow deforms canonical dynamics, linking decoherence, dissipation, and gravitational curvature. TEQ reinterprets physical law as emergent structure within the geometry of distinguishability, rather than as imposed dynamics on a fixed spacetime background.
This paper introduces the Total Entropic Quantity (TEQ) framework, a structural reformulation of quantum theory grounded in two foundational axioms. Axiom 0 posits entropy as a generative constraint: a geometric principle that determines which configurations can stably distinguish themselves, independent of space, time, or dynamics. Here, entropy is defined as a curvature-functional over distinguishability configurations, preserving only those patterns that remain stable under finite informational resolution---that is, structures not dissolved by coarse-graining or limited observability. Axiom 1, the Minimal Principle (MP), selects from these structures those that are maximally stable under entropy-weighted variation. From this entropic foundation, core elements of quantum theory---including the Born rule, quantization, and Schrödinger dynamics---emerge as special cases of entropy-stabilized geometry. The framework derives an entropy-weighted path integral and introduces a corrected Schrödinger equation that governs evolution in regimes of finite entropy curvature. In the high-resolution limit (β→∞), TEQ reduces to standard unitary quantum mechanics; in more general regimes, entropy flow deforms canonical dynamics, linking decoherence, dissipation, and gravitational curvature. TEQ reinterprets physical law as emergent structure within the geometry of distinguishability, rather than as imposed dynamics on a fixed spacetime background.
Abstract This work develops a process-based framework for quantum gravity in which physical space is rigorously described as the topology of a dynamically evolving graph of discrete quantum processes called P-tacts. A P-tact is defined as the primitive unit of quantum evolution, unifying local superposition and entangling operations into a single indivisible process step. Within this formalism, spacetime is not assumed as a pre-existing background but emerges from the connectivity structure of entanglement relations between P-tacts. The present study synthesizes and extends a coherent research program published throughout 2026. The foundational definition of the P-tact as the primitive unit of quantum theory was introduced in: Pavlov, M. (2026). P Tact (П-такт) as the Primitive Unit of Quantum Theory. Zenodo.https://doi.org/10.5281/zenodo.18516711 The emergence of the quantum switch as a process structure and the reconstruction of indefinite causal order were developed in: Pavlov, M. (2026). Quantum Switch as an Emergent Process Structure from Discrete Process Tacts (П-такт).https://doi.org/10.5281/zenodo.18498181 Pavlov, M. (2026). Indefinite Causal Order as Superposition of Process Graphs.https://doi.org/10.5281/zenodo.18519010 Pavlov, M. (2026). From Indefinite Causal Order to Definite Process Order: A Topological Reconstruction of the Quantum Switch via Discrete P-Tacts (П-такт).https://doi.org/10.5281/zenodo.18526959 Pavlov, M. (2026). Quantum Switch as a Minimal P Tact (П-такт) Cycle.https://doi.org/10.5281/zenodo.18607385 The connection between P-tacts, teleportation, and non-classical causal structures was presented in: Pavlov, M. (2026). Quantum Switch and Teleportation.https://doi.org/10.5281/zenodo.18509173 The emergence of time, causality, gravity, and three-dimensional space from discrete P-tact dynamics was developed in: Pavlov, M. (2026). Emergence of Causality, Gravity, Time, and Three-Dimensional Space from Discrete P-Tact (П-такт) Dynamics.https://doi.org/10.5281/zenodo.18504244 Pavlov, M. (2026). Emergence of Time from P Tact Entanglement (Происхождение времени).https://doi.org/10.5281/zenodo.18526015 Pavlov, M. (2026). Causality and Arrow of Time.https://doi.org/10.5281/zenodo.18549931 The Everett interpretation was explicitly formalized within the P-tact graph framework in: Pavlov, M. (2026). Everett Interpretation Formalized via P-Tact (П-такт) Path Graphs.https://doi.org/10.5281/zenodo.18524745 The present work integrates these results into a unified topological model in which space is identified with graph connectivity, curvature corresponds to dynamic restructuring of entanglement relations, and gravitational phenomena emerge as large-scale patterns of connectivity evolution. In this framework, geometry is not fundamental but process-derived. The theory is fully compatible with Everettian quantum mechanics and eliminates the need for wavefunction collapse. Branching structures correspond to graph bifurcations in the P-tact network, providing a structural representation of many-world dynamics. Gravity is thus interpreted not as a fundamental interaction but as an emergent property of quantum process topology. This approach proposes a formally consistent, unitary, and experimentally testable pathway toward quantum gravity grounded entirely in discrete quantum processes. Potential experimental implementations include quantum simulators and BQM platforms capable of modeling evolving entanglement graphs.