arXiv subjects

Mike Stannett

Publications and source records attributed to Mike Stannett.

15 recordsLinked to original sources

arXiv2026

Definability from Factorised Symmetry in Ultrapowers

A recent theorem of Madarasz characterises the parameter-free concepts of a finitely field-definable coordinate geometry by invariance under its affine automorphisms. This paper isolates the affine-geometric ingredient in that proof and extends the argument to include additional finite-relational coordinate geometries. The new hypothesis is "semilinear faithfulness": in every ultrapower, each automorphism of the induced geometry factors as an affine automorphism of the geometry followed by the componentwise action of an automorphism of the expanded base structure. Under this hypothesis, every parameter-free ambient-definable relation is a concept of the geometry exactly when it is preserved by the affine automorphism group. A corresponding dual inclusion theorem is obtained for concept sets. The framework recovers the original finitely field-definable theorem and applies beyond pure-field definability, including a named-scalar geometry and a frame-expanded geometry over an exponential field. A final section records the analogous factorisation principle for uniformly coded symmetry groups in arbitrary, including non-geometric, one-sorted structures.

math.LO↗

arXiv2026

Groups of Worldview Transformations Implied by Einstein's Special Principle of Relativity over Arbitrary Ordered Fields

In 1978, Yu. F. Borisov presented an axiom system using a few basic assumptions and four explicit axioms, the fourth being a formulation of the relativity principle; and he demonstrated that this axiom system had (up to choice of units) only two models: a relativistic one in which worldview transformations are Poincaré transformations and a classical one in which they are Galilean. In this paper, we reformulate Borisov's original four axioms within an intuitively simple, but strictly formal, first-order logic framework, and convert his basic background assumptions into explicit axioms. Instead of assuming that the structure of physical quantities is the field of real numbers, we assume only that they form an ordered field. This allows us to investigate how Borisov's theorem depends on the structure of quantities. We demonstrate (as our main contribution) how to construct Euclidean, Galilean, and Poincaré models of Borisov's axiom system over every non-Archimedean field. We also demonstrate the existence of an infinite descending chain of models and transformation groups in each of these three cases, something that is not possible over Archimedean fields. As an application, we note that there is a model of Borisov's axioms that satisfies the relativity principle, and in which the worldview transformations are Euclidean isometries. Over the field of reals it is easy to eliminate this model using natural axioms concerning time's arrow and the absence of instantaneous motion. In the case of non-Archimedean fields, however, the Euclidean isometries appear intrinsically as worldview transformations in models of Borisov's axioms and neither the assumption of time's arrow, nor the rejection of instantaneous motion, can eliminate them.

physics.gen-ph↗

arXiv2026

A Stone-Cech Collecting Semantics for Residual Process Behaviour

This paper develops a compact collecting semantics for the residual behaviour left by nonterminating computation. For sequential time this is the tail-cluster set of the stream in the Stone-Cech compactification of the observation space. It gives a common semantics to ordinary recurrence, mixed recurrent behaviour, and escape through noncompact parts of the observation space. The basic theory establishes tail invariance, functoriality under continuous observations, and a temporal reading for clopen observations: containment in the corresponding clopen region of beta-X is eventual truth, while nonempty intersection is recurrence. Progress and fairness assumptions are represented by strengthening the time filter. Relational meanings are obtained by compactifying products, so correlations between observations made along the same asymptotic view of time are retained. The main application is to residual behaviour in CCS. Infinite executions are read as streams of residual processes modulo structural congruence. The resulting semantics distinguishes stable divergence, finite recurrent divergence, mixed recurrence with escape, and escape through unbounded residual growth. It validates residual-tail laws for prefixing, guarded unfolding, finite choice, and finite prefix-choice forms, while also identifying the boundary of those laws under parallel composition and synchronisation. Finite observational quotients provide the computational interface to the compact semantics: abstract meanings become recurrent states and strongly connected component calculations, and resource observations detect unbounded escape without requiring individual points of the Stone-Cech remainder to be inspected.

cs.LO↗

arXiv2025

On Andréka's Conjecture that special relativity is the only possible conceptual reduct of classical kinematics

In this paper, we prove a pure mathematical result which has important implications for the history and philosophy of classical physics and the conceptual origins of relativity theory. In formal terms, we show that, up to definitional equivalence, there is no intermediate model of spacetime lying strictly between special relativity and late classical kinematics. Informally, this means that there was essentially no other option but to switch to special relativity to resolve the conflict between late classical kinematics and the null result of the Michelson--Morley experiment.

math-ph↗

arXiv2025

Definable coordinate geometries over fields, part 1: theory

We define general notions of coordinate geometries over fields and ordered fields, and consider coordinate geometries that are given by finitely many relations that are definable over those fields. We show that the automorphism group of such a geometry determines the geometry up to definitional equivalence; moreover, if we are given two such geometries $\mathcal{G}$ and $\mathcal{G}'$, then the concepts (explicitly definable relations) of $\mathcal{G}$ are concepts of $\mathcal{G}'$ exactly if the automorphisms of $\mathcal{G}'$ are automorphisms of $\mathcal{G}$. We show this by first proving that a relation is a concept of $\mathcal{G}$ exactly if it is closed under the automorphisms of $\mathcal{G}$ and is definable over the field; moreover, it is enough to consider automorphisms that are affine transformations.

math.LO↗

arXiv2025

Definable coordinate geometries over fields, part 2: applications

In Part 1 of this study we showed, for a wide range of geometries, that the relationships between their concept-sets are fully determined by those between their (affine) automorphism groups. In this (self-contained) part, we show how this result can be applied to quickly determine relationships and differences between various geometries and spacetimes, including ordered affine, Euclidean, Galilean, Newtonian, Late Classical, Relativistic and Minkowski spacetimes (we first define these spacetimes and geometries using a Tarskian first-order language centred on the ternary relation $\mathsf{Bw}$ of betweenness). We conclude with a selection of open problems related to the existence of certain intermediate geometries.

math.LO↗

arXiv2020

Groups of Worldview Transformations Implied by Isotropy of Space

Given any Euclidean ordered field, $Q$, and any 'reasonable' group, $G$, of (1+3)-dimensional spacetime symmetries, we show how to construct a model $M_{G}$ of kinematics for which the set $W$ of worldview transformations between inertial observers satisfies $W=G$. This holds in particular for all relevant subgroups of $Gal$, $cPoi$, and $cEucl$ (the groups of Galilean, Poincaré and Euclidean transformations, respectively, where $c\in Q$ is a model-specific parameter orresponding to the speed of light in the case of Poincaré transformations). In doing so, by an elementary geometrical proof, we demonstrate our main contribution: spatial isotropy is enough to entail that the set $W$ of worldview transformations satisfies either $W\subseteq Gal$, $W\subseteq cPoi$, or $W\subseteq cEucl$ for some $c>0$. So assuming spatial isotropy is enough to prove that there are only 3 possible cases: either the world is classical (the worldview transformations between inertial observers are Galilean transformations); the world is relativistic (the worldview transformations are Poincaré transformations); or the world is Euclidean (which gives a nonstandard kinematical interpretation to Euclidean geometry). This result considerably extends previous results in this field, which assume a priori the (strictly stronger) special principle of relativity, while also restricting the choice of $Q$ to the field of reals. As part of this work, we also prove the rather surprising result that, for any $G$ containing translations and rotations fixing the time-axis $t$, the requirement that $G$ be a subgroup of one of the groups $Gal$, $cPoi$ or $cEucl$ is logically equivalent to the somewhat simpler requirement that, for all $g\in G$: $g[t]$ is a line, and if $g[t]=t$ then $g$ is a trivial transformation (i.e. $g$ is a linear transformation that preserves Euclidean length and fixes the time-axis setwise).

math-ph↗

arXiv2017

Three Different Formalisations of Einstein's Relativity Principle

We present three natural but distinct formalisations of Einstein's special principle of relativity, and demonstrate the relationships between them. In particular, we prove that they are logically distinct, but that they can be made equivalent by introducing a small number of additional, intuitively acceptable axioms.

physics.class-ph↗

arXiv2014

Developing a Video Steganography Toolkit

Although techniques for separate image and audio steganography are widely known, relatively little has been described concerning the hiding of information within video streams ("video steganography"). In this paper we review the current state of the art in this field, and describe the key issues we have encountered in developing a practical video steganography system. A supporting video is also available online at http://www.youtube.com/watch?v=YhnlHmZolRM

cs.MM↗

arXiv2014

Integration Testing of Heterotic Systems

Computational theory and practice generally focus on single-paradigm systems, but relatively little is known about how best to combine components based on radically different approaches (e.g., silicon chips and wetware) into a single coherent system. In particular, while testing strategies for single-technology components are generally well developed, it is unclear at present how to perform integration testing on heterotic systems: can we develop a test-set generation strategy for checking whether specified behaviours emerge (and unwanted behaviours do not) when components based on radically different technologies are combined within a single system? In this paper, we describe an approach to modelling multi-technology heterotic systems using a general-purpose formal specification strategy based on Eilenberg's X-machine model of computation. We show how this approach can be used to represent disparate technologies within a single framework, and propose a strategy for using these formal models for automatic heterotic test-set generation. We illustrate our approach by showing how to derive a test set for a heterotic system combining an X-machine-based device with a cell-based P system (membrane system).

cs.ET↗

arXiv2014

Why Do the Relativistic Masses and Momenta of Faster-than-Light Particles Decrease as their Speeds Increase?

It has recently been shown within a formal axiomatic framework using a definition of four-momentum based on the Stückelberg-Feynman-Sudarshan-Recami "switching principle" that Einstein's relativistic dynamics is logically consistent with the existence of interacting faster-than-light inertial particles. Our results here show, using only basic natural assumptions on dynamics, that this definition is the only possible way to get a consistent theory of such particles moving within the geometry of Minkowskian spacetime. We present a strictly formal proof from a streamlined axiom system that given any slow or fast inertial particle, all inertial observers agree on the value of $\mathsf{m}\cdot \sqrt{|1-v^2|}$, where $\mathsf{m}$ is the particle's relativistic mass and $v$ its speed. This confirms formally the widely held belief that the relativistic mass and momentum of a positive-mass faster-than-light particle must decrease as its speed increases.

gr-qc↗

arXiv2013

Using Isabelle to verify special relativity, with application to hypercomputation theory

Logicians at the Rényi Mathematical Institute in Budapest have spent several years developing versions of relativity theory (special, general, and other variants) based wholly on first order logic, and have argued in favour of the physical decidability, via exploitation of cosmological phenomena, of formally undecidable questions such as the Halting Problem and the consistency of set theory. The Hungarian theories are very extensive, and their associated proofs are intuitively very satisfying, but this brings its own risks since intuition can sometimes be misleading. As part of a joint project, researchers at Sheffield have recently started generating rigorous machine-verified versions of the Hungarian proofs, so as to demonstrate the soundness of their work. In this paper, we explain the background to the project and demonstrate an Isabelle proof of the theorem "No inertial observer can travel faster than light". This approach to physical theories and physical computability has several pay-offs: (a) we can be certain our intuition hasn't led us astray (or if it has, we can identify where this has happened); (b) we can identify which axioms are specifically required in the proof of each theorem and to what extent those axioms can be weakened (the fewer assumptions we make up-front, the stronger the results); and (c) we can identify whether new formal proof techniques and tactics are needed when tackling physical as opposed to mathematical theories.

cs.LO↗

arXiv2011

Computation and Spacetime Structure

We investigate the relationship between computation and spacetime structure, focussing on the role of closed timelike curves (CTCs) in promoting computational speedup. We note first that CTC traversal can be interpreted in two distinct ways, depending on ones understanding of spacetime. Focussing on one interpretation leads us to develop a toy universe in which no CTC can be traversed more than once, whence no computational speedup is possible. Focussing on the second (and more standard) interpretation leads to the surprising conclusion that CTCs act as perfect information repositories: just as black holes have entropy, so do CTCs. If we also assume that P is not equal to NP, we find that all observers agree that, even if unbounded time travel existed in their youth, this capability eventually vanishes as they grow older. Thus the computational assumption "P is not NP" is also an assumption concerning cosmological structure.

gr-qc↗

arXiv2009

Modelling Quantum Theoretical Trajectories within Geometric Relativistic Theories

Andreka and her colleagues have described various geometrically inspired first-order theories of special and general relativity, while Szekely's PhD dissertation focuses on an intermediate logic of accelerated observers. In this paper we will attempt to incorporate a model of quantum theoretical trajectories that can reasonably claim to be physically meaningful into those theories. We have recently shown that a model of quantum trajectories, based on discrete finitary motion, is logically equivalent to Feynman's path-integral formulation when spacetime is assumed to be Euclidean. In this paper we argue that relativistic observers are subject to the same quantum illusions as in the Euclidean case: even though motion is discrete and respects no built-in 'arrow of time', observers have no choice but to perceive particle trajectories as continuous paths in spacetime. Whereas the relativistic theories presuppose continuous paths as part of their axioms, the illusion of continuity allows us to replace this axiom with a lower-level quantum-inspired axiom concerning discrete jumps in spacetime. We investigate the nature of these jumps, and how far they can be tied to the underlying geometric structure of spacetime. In particular, we consider hops which preserve features of the underlying number field, and investigate the extent to which all hops can be restricted to be of this form. We conclude that hop-based motion can also be regarded as an illusion, one caused by modelling physics in the 'wrong' number system.

gr-qc↗

arXiv2008

The Computational Status of Physics: A Computable Formulation of Quantum Theory

According to the Church-Turing Thesis (CTT), effective formal behaviours can be simulated by Turing machines; this has naturally led to speculation that physical systems can also be simulated computationally. But is this wider claim true, or do behaviours exist which are strictly hypercomputational? Several idealised computational models are known which suggest the possibility of hypercomputation, some Newtonian, some based on cosmology, some on quantum theory. While these models' physicality is debatable, they nonetheless throw into question the validity of extending CTT to include all physical systems. We consider the physicality of hypercomputational behaviour from first principles, by showing that quantum theory can be reformulated in a way that explains why physical behaviours can be regarded as 'computing something' in the standard computational state-machine sense. While this does not rule out the physicality of hypercomputation, it strongly limits the forms it can take. Our model also has physical consequences; in particular, the continuity of motion and arrow of time become theorems within the basic model.

quant-ph↗