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Algebraic Quantum Field Theory

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lightbulbAbout this topic
Algebraic Quantum Field Theory (AQFT) is a framework in theoretical physics that formulates quantum field theories using the mathematical language of operator algebras. It emphasizes the algebraic structure of observables and states, providing a rigorous foundation for the study of quantum fields in a manner that is independent of specific spacetime models.
lightbulbAbout this topic
Algebraic Quantum Field Theory (AQFT) is a framework in theoretical physics that formulates quantum field theories using the mathematical language of operator algebras. It emphasizes the algebraic structure of observables and states, providing a rigorous foundation for the study of quantum fields in a manner that is independent of specific spacetime models.

Key research themes

1. How does algebraic quantum field theory (AQFT) formulate quantum field theory in curved spacetime and ensure physically meaningful states?

This theme focuses on the algebraic formulation of quantum field theory on globally hyperbolic curved spacetimes. It studies how observable algebras are defined independently of a fixed Hilbert space, how Hadamard states characterize physically reasonable quasifree states, and the construction and properties of CCR algebras and symmetry-induced *-algebra homomorphisms. This is crucial for generalizing QFT beyond Minkowski spacetime while retaining mathematical rigor and physical interpretability.

Key finding: The paper introduces the algebraic formalism of QFT on globally hyperbolic curved spacetimes via unital *-algebras generated by smeared fields obeying CCR relations. It emphasizes the utility of dealing with *-algebras rather... Read more
Key finding: Utilizing the pAQFT framework, the paper constructs the local algebras of the massless Sine-Gordon model directly in Lorentzian signature without Wick rotation, demonstrating convergence of the formal S-matrix and interacting... Read more
Key finding: The paper presents the algebraic second quantization functor mapping free linear symplectic phase spaces into Weyl-Heisenberg algebras and constructs locally covariant nets of von Neumann algebras for free quantum fields on... Read more

2. What is the role of modular theory and non-commutative geometry in providing a deeper geometric and quantum structure to space-time within AQFT?

This theme investigates how Tomita-Takesaki modular theory and related operator-algebraic structures reveal hidden dynamics and geometric structures of quantum field theories, suggesting a noncommutative and modularly quantized space-time framework. The approach leverages modular automorphisms, KMS states, and generalizations of classical geometries (e.g. Tulczyjew double bundles, Hitchin-Gualtieri bundles) to link algebraic quantum gravity proposals to quantum geometry and offers speculation on 'quantum geometry' emerging directly from AQFT's modular data.

Key finding: By employing Tomita-Takesaki modular theory applied to local operator algebras and states, the paper uncovers intrinsic modular automorphism groups encoding noncommutative geometric structures of quantum phase space. It... Read more
Key finding: The work links AQFT constructions of local algebras with Tomita-Takesaki modular theory, showing that modular conjugations and modular automorphism groups yield intrinsic dynamical symmetries possibly interpretable as quantum... Read more
Key finding: The modular algebraic quantum gravity conjecture presented formulates that the classical Riemannian geometry's complexifications yield canonical gauge modular flows on generalized tangent bundles, potentially encoding quantum... Read more

3. How can the algebraic formalism of quantum field theory link to more traditional quantum mechanics and abstract algebraic structures like Lie algebras and generalized functions?

This theme covers the connection between quantum field theory operators and canonical quantum mechanical operators, the role of algebraic structures such as Lie algebras in phase-space quantization, and the use of nonlinear generalized functions to properly capture nonlinear operations on distributions appearing in QFT. The insight here is bridging practical quantum computations with deep algebraic frameworks and extending the algebraic language (Weyl algebras, Wigner-Weyl-Moyal formalism) to broader algebraic and geometric contexts.

Key finding: The paper constructs an explicit algebraic embedding of the canonical position and momentum operators for N identical particles in Quantum Mechanics from field operators of the free Klein-Gordon quantum field. It proves these... Read more
Key finding: This paper extends the Wigner-Weyl-Moyal quantization formalism from canonical phase space defined by Heisenberg Lie algebras to arbitrary Lie algebras and super Lie algebras, introducing corresponding translation operators... Read more
Key finding: The paper advocates the use of nonlinear generalized functions as a mathematically consistent framework to handle the nonlinear operations on distributions arising in canonical quantization of fields (Heisenberg-Pauli... Read more

All papers in Algebraic Quantum Field Theory

Аннотация: С помощью, специального алгоритма,принципа многоуровневой периодичности, обнаружено периодическое изменение свойств на уровне ядер химических элементов и представлен вариант периодической системы изотопов. Выполнена проверка... more
This paper examines strong operator convergence through its master equation formulation and associated variance bounds. The work develops the mathematical framework governing this convergence mode and its implications for expectation... more
We extend the observer-relative formulation of black hole complementarity by integrating TomitaTakesaki modular theory into the geometric structure of causal diamonds. By treating modular time as a connection over diamond-space, we show... more
This paper revisits black-hole complementarity using Rovelli's relational quantum mechanics within the algebraic framework of quantum field theory in curved spacetime. For each observer, we construct a local von Neumann algebra as the... more
This paper proposes an extended framework unifying Hameroff-Penrose's Orchestrated Objective Reduction (Orch-OR) with a novel Unified Coherence Field (ψ C). We derive the quantum dynamics of microtubule coherence and couple ψ C to... more
This work establishes a rigorous field-theoretic framework for consciousness-cosmos interaction through: • A non-local quantum coherence field ψC with Hubble-scale correlation length • Microtubule-mediated decoherence channels in neural... more
We propose a unified geometric framework extending classical spacetime to a 64dimensional manifold, integrating quantum gravity effects, higher-dimensional topology, and a novel interpretation of dark matter. This model introduces a... more
A link between quantization and (non-commutative) geometry is uncovered via Tomita-Takesaki modular theory for complexified ortho-symplectic spaces. We suggest (following arXiv:1007.4094v1) that, in a covariant quantum theory,... more
The periodic system of chemical elements is represented within the framework of the weight diagram of the Lie algebra of the fourth rank of the rotation group of an eight-dimensional pseudo-Euclidean space. Spin is interpreted as the... more
В данной статье анализируется фундаментальное отличие полей Σ, ℂ и ℍ от векторных пространств. Особое внимание уделяется критике введения операции умножения вектора на вектор («кросс-» или «буравчиковое» умножение) в этих алгебрах как... more
В статье предложена интерпретация двумерных алгебр, описанных в труде С.С. Кокарева и Д. Павлова, через геометрическую структуру устройства Сфираль. Сфираль рассматривается как физическая реализация алгебраических отношений:... more
The periodic system of chemical elements is represented within the framework of the weight diagram of the Lie algebra of the fourth rank of the rotation group of an eightdimensional pseudo-Euclidean space. The hydrogen realization of the... more
We give a non-perturbative construction of the fermionic projector in Minkowski space coupled to a time-dependent external potential which is smooth and decays faster than quadratically for large times. The weak and strong mass... more
A common misunderstanding, one of which we need to disabuse ourselves, is that quantum theory, while possessing astounding predictive power, actually explains the phenomena it describes. It does not. Quantum theory offers mathematical... more
We investigate the notion of subsystem in the framework of spectral triple as a generalized notion of noncommutative submanifold. In the case of manifolds, we consider several conditions on Dirac operators which turn embedded submanifolds... more
- A deep link between quantization and (non-commutative) geometry is uncovered via a careful usage of modular theory. - It is premature to assume that space-time geometry in quantum gravity becomes relevant only at the emergent... more
We take a look at the “forbidden route” backward from the Wilsonian/Feynmanian paradigm in (effective) quantum field theory and emergent geometry in quantum gravity. Our rear-ward exploration of the forgotten origins of quantum (field)... more
We review the status and current prospects of Modular Algebraic Quantum Gravity arXiv:1007.4094v1). - It is premature to assume that space-time geometry in QG becomes relevant only at the emergent macroscopic level. - At the covariant... more
We informally describe a circle of still conjectural ideas (that have been the central motivation for my research) on the intrinsic reconstruction of quantum space-time from a state on a category of partial observables, via modular... more
Diffeologies, introduced by J.-M.Souriau, are a vast generalization of smooth manifolds that, from the point of view of category theory, is much better behaved. Not much is known on the possible ways to describe such spaces in the... more
We prove that a certain bialgebroid introduced recently by Kadison is isomorphic to a bialgebroid introduced earlier by Connes and Moscovici. At the level of total algebras, the isomorphism is a consequence of the general fact that an... more
Recently, it has been shown that the quantum equilibrium distribution in the original Bohm's model is unstable and so it isn't a tenable physical theory [Proc. R. Soc. A 470 20140288 (2014)]. In this paper we show that a natural... more
A new non-Archimedean approach to interacted quantum fields is presented. In proposed approach, a field operator , no longer a standard tempered operator-valued distribution, but a non-classical operator-valued function. We prove using... more
The root structure of the subalgebras of the group algebra of a conformal group in the framework of a twofold covering is analyzed. Based on the analysis, the Cartan–Weyl basis of the group algebra is determined. The root and weight... more
The Higgs mechanism is invoked to explain how gauge bosons can be massive while Yang-Mills theory describes only massless gauge fields. Central to it is the notion of spontaneous symmetry breaking (SSB), applied to the SU(2) × U(1) gauge... more
We compare the relative merites of algebraic quantum field theory (AQFT) and conventional quantum field theory (CQFT) as frameworks for the philosophy of quantum field theory.
The structure of the group algebra of a conformal group (the group underlying the group-theoretic description of the periodic system of chemical elements) is considered within the framework of a twofold covering. The hydrogen realization... more
After reviewing the theory of "causal fermion systems" (CFS theory) and the "Events, Trees, and Histories Approach" to quantum theory (ETH approach), we compare some of the mathematical structures underlying these two general frameworks... more
Recently, examples of an index theory for KMS states of circle actions were discovered, [9, 13]. We show that these examples are not isolated. Rather there is a general framework in which we use KMS states for circle actions on a C... more
L'accès aux archives de la revue « Annales de l'I. H. P., section A » implique l'accord avec les conditions générales d'utilisation (http://www.numdam. org/conditions). Toute utilisation commerciale ou impression systématique est... more
Present day physics rests on two main pillars: General relativity and quantum field theory. We discuss the deep and at the same time problematic interplay between these two theories. Based on an argument by Doplicher, Fredenhagen and... more
Pimsner introduced the C *-algebra O X generated by a Hilbert bimodule X over a C *-algebra A. We look for additional conditions that X should satisfy in order to study the simplicity and, more generally, the ideal structure of O X when X... more
The questions of interpretation of the algebraic formulation of a quantum theory with a binary structure are considered. The possibility of constructing a quantum theory without using any classical analogies and visual images and... more
We propose an alternative representation for linear quantum gravity. It is based on the use of a structure that bears some resemblance to the Abelian loop representation used in electromagnetism but with the difference that the space of... more
We propose a profound consequence of symmetry towards the axiomatic derivation of Hilbert space quantum theory. Specifically, we show that the symmetry of information gain in minimal error state discrimination induces a non-trivial... more
Symmetry shares an entwined history with the structure of physical theory. We propose a consequence of symmetry towards the axiomatic derivation of Hilbert space quantum theory. We introduce the notion of information symmetry (IS) and... more
We present a numerical approximation scheme for the Tomita-Takesaki modular operator of local subalgebras in linear quantum fields, working at one-particle level. This is applied to the local subspaces for double cones in the vacuum... more
We analyze the algebraic, topological, and order properties of /*-algebras: complex unital topological *-algebras for which S^/*^/=0 implies #f=0 (Je/), JcJV any finite subset. We consider the ergodic properties of states on an I*-algebra... more
We consider the positive energy representations of the algebra of quasilocal observables for the free massless Majorana field described in preceding papers [1,2]. We show that by an appropriate choice of the (partially) occupied one... more
This paper is dedicated to a detailed analysis and computation of quantum states of causal fermion systems. The mathematical core is to analyze integrals over the unitary group asymptotically for a large dimension of the group, for... more
We give a functional analytic construction of the fermionic projector on a globally hyperbolic Lorentzian manifold of finite lifetime. The integral kernel of the fermionic projector is represented by a two-point distribution on the... more
Causal variational principles, which are the analytic core of the physical theory of causal fermion systems, are found to have an underlying Hamiltonian structure, giving a formulation of the dynamics in terms of physical fields in... more
We consider a structure of the K-Hilbert space, where K ≃ R is a field of real numbers, K ≃ C is a field of complex numbers, K ≃ H is a quaternion algebra, within the framework of division rings of Clifford algebras. The K-Hilbert space... more
Обсуждается проблема построения эффективного алгоритма обращения целочисленной матрицы. Один из способов вычисления обратной матрицы опирается на предварительное вычисление матрицы Смита. Известен вероятностный алгоритм вычисления матрицы... more
Due to an example indicated to us in September 2009 we have to add one more restriction to the suppositions on the imprimitivity bimodules treated in Proposition 4.1, Theorem 5.1, Theorem 6.2 and Proposition 6.3. In the situation when the... more
It is shown that uncertainty relations, as well as coherent and squeezed states, are structural properties of stochastic processes with Fokker-Planck dynamics. The quantum mechanical coherent and squeezed states are explicitly constructed... more
It is shown that uncertainty relations, as well as coherent and squeezed states, are structural properties of stochastic processes with Fokker-Planck dynamics. The quantum mechanical coherent and squeezed states are explicitly constructed... more
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