{"title":"The Quantization of Proca Fields on Globally Hyperbolic Spacetimes: Hadamard States and Møller Operators","authors":"Valter Moretti, Simone Murro, Daniele Volpe","doi":"10.1007/s00023-023-01326-w","DOIUrl":"10.1007/s00023-023-01326-w","url":null,"abstract":"<div><p>This paper deals with several issues concerning the algebraic quantization of the real Proca field in a globally hyperbolic spacetime and the definition and existence of Hadamard states for that field. In particular, extending previous work, we construct the so-called M?ller <span>(*)</span>-isomorphism between the algebras of Proca observables on paracausally related spacetimes, proving that the pullback of these isomorphisms preserves the Hadamard property of corresponding quasifree states defined on the two spacetimes. Then, we pull back a natural Hadamard state constructed on ultrastatic spacetimes of bounded geometry, along this <span>(*)</span>-isomorphism, to obtain an Hadamard state on a general globally hyperbolic spacetime. We conclude the paper, by comparing the definition of an Hadamard state, here given in terms of wavefront set, with the one proposed by Fewster and Pfenning, which makes use of a supplementary Klein–Gordon Hadamard form. We establish an (almost) complete equivalence of the two definitions.</p></div>","PeriodicalId":463,"journal":{"name":"Annales Henri Poincaré","volume":"24 9","pages":"3055 - 3111"},"PeriodicalIF":1.5,"publicationDate":"2023-05-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s00023-023-01326-w.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"5130187","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Quand Galilée et Carroll engendrent Lorentz","authors":"Jean-Marc Lévy-Leblond","doi":"10.1007/s00023-023-01321-1","DOIUrl":"10.1007/s00023-023-01321-1","url":null,"abstract":"<div><h2>Résumé</h2><div><p>Le présent article montre l’existence d’une inédite relation suggestive entre le groupe de Lorentz et ses cousins dégénérés, les groupes de Galilée et de Carroll.</p></div></div>","PeriodicalId":463,"journal":{"name":"Annales Henri Poincaré","volume":"24 9","pages":"3209 - 3213"},"PeriodicalIF":1.5,"publicationDate":"2023-05-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"4584868","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Hanno Gottschalk, Nicolai R. Rothe, Daniel Siemssen
{"title":"Cosmological de Sitter Solutions of the Semiclassical Einstein Equation","authors":"Hanno Gottschalk, Nicolai R. Rothe, Daniel Siemssen","doi":"10.1007/s00023-023-01315-z","DOIUrl":"10.1007/s00023-023-01315-z","url":null,"abstract":"<div><p>Exponentially expanding space–times play a central role in contemporary cosmology, most importantly in the theory of inflation and in the dark energy driven expansion in the late universe. In this work, we give a complete list of de Sitter solutions of the semiclassical Einstein equation (SCE), where classical gravity is coupled to the expected value of a renormalized stress–energy tensor of a free quantum field in the Bunch–Davies state. To achieve this, we explicitly determine the stress–energy tensor associated with the Bunch–Davies state using the recently proposed “moment approach” on the cosmological coordinate patch of de Sitter space. From the energy component of the SCE, we thus obtain an analytic consistency equation for the model’s parameters which has to be fulfilled by solutions to the SCE. Using this equation, we then investigate the number of solutions and the structure of the solution set in dependency on the coupling parameter of the quantum field to the scalar curvature and renormalization constants using analytic arguments in combination with numerical evidence. We also identify parameter sets where multiple expansion rates separated by several orders of magnitude are possible. Potentially for such parameter settings, a fast (semi-stable) expansion in the early universe could be compatible with a late-time “Dark Energy-like” behavior of the universe.</p></div>","PeriodicalId":463,"journal":{"name":"Annales Henri Poincaré","volume":"24 9","pages":"2949 - 3029"},"PeriodicalIF":1.5,"publicationDate":"2023-05-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s00023-023-01315-z.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"4394112","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Tilahun Deneke, Tamirat T. Dufera, Achenef Tesfahun
{"title":"Dispersive Estimates for Linearized Water Wave-Type Equations in (mathbb {R}^d)","authors":"Tilahun Deneke, Tamirat T. Dufera, Achenef Tesfahun","doi":"10.1007/s00023-023-01322-0","DOIUrl":"10.1007/s00023-023-01322-0","url":null,"abstract":"<div><p>We derive a <span>(L^1_x (mathbb {R}^d)-L^{infty }_x (mathbb {R}^d))</span> decay estimate of order <span>(mathcal O left( t^{-d/2}right) )</span> for the linear propagators </p><div><div><span>$$begin{aligned} exp left( {pm it sqrt{ |D|left( 1+ beta |D|^2right) tanh |D | } }right) , qquad beta in {0, 1}. quad D= -inabla , end{aligned}$$</span></div></div><p>with a loss of 3<i>d</i>/4 or <i>d</i>/4–derivatives in the case <span>(beta =0)</span> or <span>(beta =1)</span>, respectively. These linear propagators are known to be associated with the linearized water wave equations, where the parameter <span>(beta )</span> measures surface tension effects. As an application, we prove low regularity well-posedness for a Whitham–Boussinesq-type system in <span>(mathbb {R}^d)</span>, <span>(dge 2)</span>. This generalizes a recent result by Dinvay, Selberg and the third author where they proved low regularity well-posedness in <span>(mathbb {R})</span> and <span>(mathbb {R}^2)</span>.</p></div>","PeriodicalId":463,"journal":{"name":"Annales Henri Poincaré","volume":"24 11","pages":"3741 - 3761"},"PeriodicalIF":1.5,"publicationDate":"2023-05-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41229270","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Henning Bostelmann, Daniela Cadamuro, Christoph Minz
{"title":"On the Mass Dependence of the Modular Operator for a Double Cone","authors":"Henning Bostelmann, Daniela Cadamuro, Christoph Minz","doi":"10.1007/s00023-023-01311-3","DOIUrl":"10.1007/s00023-023-01311-3","url":null,"abstract":"<div><p>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 sector of a massive scalar free field in <span>((1+1))</span>- and <span>((3+1))</span>-dimensional Minkowski spacetime, using a discretization of time-0 data in position space. In the case of a wedge region, one component of the modular generator is well known to be a mass-independent multiplication operator; our results strongly suggest that for the double cone, the corresponding component is still at least close to a multiplication operator, but that it is dependent on mass and angular momentum.</p></div>","PeriodicalId":463,"journal":{"name":"Annales Henri Poincaré","volume":"24 9","pages":"3031 - 3054"},"PeriodicalIF":1.5,"publicationDate":"2023-05-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s00023-023-01311-3.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"4515108","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Anisotropic Spin Generalization of Elliptic Macdonald–Ruijsenaars Operators and R-Matrix Identities","authors":"M. Matushko, Andrei Zotov","doi":"10.1007/s00023-023-01316-y","DOIUrl":"10.1007/s00023-023-01316-y","url":null,"abstract":"<div><p>We propose commuting set of matrix-valued difference operators in terms of the elliptic Baxter–Belavin <i>R</i>-matrix in the fundamental representation of <span>(textrm{GL}_M)</span>. In the scalar case <span>(M=1)</span>, these operators are the elliptic Macdonald–Ruijsenaars operators, while in the general case they can be viewed as anisotropic versions of the quantum spin Ruijsenaars Hamiltonians. We show that commutativity of the operators for any <i>M</i> is equivalent to a set of <i>R</i>-matrix identities. The proof of identities is based on the properties of elliptic <i>R</i>-matrix including the quantum and the associative Yang–Baxter equations. As an application of our results, we introduce elliptic version of q-deformed Haldane–Shastry model.</p></div>","PeriodicalId":463,"journal":{"name":"Annales Henri Poincaré","volume":"24 10","pages":"3373 - 3419"},"PeriodicalIF":1.5,"publicationDate":"2023-05-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"6713781","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Lower Bound to the Entanglement Entropy of the XXZ Spin Ring","authors":"Christoph Fischbacher, Ruth Schulte","doi":"10.1007/s00023-023-01318-w","DOIUrl":"10.1007/s00023-023-01318-w","url":null,"abstract":"<div><p>We study the free XXZ quantum spin model defined on a ring of size <i>L</i> and show that the bipartite entanglement entropy of certain eigenstates belonging to the first energy band above the vacuum ground state satisfies a logarithmically corrected area law. This applies in particular to eigenstates corresponding to the lowest eigenenergy above the ground state. To this end, we develop a new perturbational approach, which allows us to control the eigenvalues of reduced states in the XXZ model in terms of the corresponding reduced states in the Ising model. Along the way, we show a Combes–Thomas estimate for fiber operators which can also be applied to discrete many-particle Schrödinger operators on more general translation-invariant graphs.</p></div>","PeriodicalId":463,"journal":{"name":"Annales Henri Poincaré","volume":"24 11","pages":"3967 - 4012"},"PeriodicalIF":1.5,"publicationDate":"2023-05-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s00023-023-01318-w.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41228958","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Integrable Degenerate (varvec{mathcal {E}})-Models from 4d Chern–Simons Theory","authors":"Joaquin Liniado, Benoît Vicedo","doi":"10.1007/s00023-023-01317-x","DOIUrl":"10.1007/s00023-023-01317-x","url":null,"abstract":"<div><p>We present a general construction of integrable degenerate <span>(mathcal {E})</span>-models on a 2d manifold <span>(Sigma )</span> using the formalism of Costello and Yamazaki based on 4d Chern–Simons theory on <span>(Sigma times {mathbb {C}}{P}^1)</span>. We begin with a physically motivated review of the mathematical results of Benini et al. (Commun Math Phys 389(3):1417–1443, 2022. https://doi.org/10.1007/s00220-021-04304-7) where a unifying 2d action was obtained from 4d Chern–Simons theory which depends on a pair of 2d fields <i>h</i> and <span>({mathcal {L}})</span> on <span>(Sigma )</span> subject to a constraint and with <span>({mathcal {L}})</span> depending rationally on the complex coordinate on <span>({mathbb {C}}{P}^1)</span>. When the meromorphic 1-form <span>(omega )</span> entering the action of 4d Chern–Simons theory is required to have a double pole at infinity, the constraint between <i>h</i> and <span>({mathcal {L}})</span> was solved in Lacroix and Vicedo (SIGMA 17:058, 2021. https://doi.org/10.3842/SIGMA.2021.058) to obtain integrable non-degenerate <span>(mathcal {E})</span>-models. We extend the latter approach to the most general setting of an arbitrary 1-form <span>(omega )</span> and obtain integrable degenerate <span>(mathcal {E})</span>-models. To illustrate the procedure, we reproduce two well-known examples of integrable degenerate <span>(mathcal {E})</span>-models: the pseudo-dual of the principal chiral model and the bi-Yang-Baxter <span>(sigma )</span>-model.\u0000</p></div>","PeriodicalId":463,"journal":{"name":"Annales Henri Poincaré","volume":"24 10","pages":"3421 - 3459"},"PeriodicalIF":1.5,"publicationDate":"2023-04-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s00023-023-01317-x.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"6713727","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Cherenkov Radiation with Massive Bosons and Quantum Friction","authors":"Mitia Duerinckx, Christopher Shirley","doi":"10.1007/s00023-023-01312-2","DOIUrl":"10.1007/s00023-023-01312-2","url":null,"abstract":"<div><p>This work is devoted to several translation-invariant models in nonrelativistic quantum field theory (QFT), describing a nonrelativistic quantum particle interacting with a quantized relativistic field of bosons. In this setting, we aim at the rigorous study of Cherenkov radiation or friction effects at small disorder, which amounts to the metastability of the embedded mass shell of the bare nonrelativistic particle when the coupling to the quantized field is turned on. Although this problem is naturally approached by means of Mourre’s celebrated commutator method, important regularity issues are known to be inherent to QFT models and restrict the application of the method. In this perspective, we introduce a novel non-standard procedure to construct Mourre conjugate operators, which differs from second quantization and allows to circumvent many regularity issues. To show its versatility, we apply this construction to the Nelson model with massive bosons, to Fröhlich’s polaron model, and to a quantum friction model with massless bosons introduced by Bruneau and De Bièvre: for each of those examples, we improve on previous results.</p></div>","PeriodicalId":463,"journal":{"name":"Annales Henri Poincaré","volume":"24 8","pages":"2743 - 2798"},"PeriodicalIF":1.5,"publicationDate":"2023-04-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s00023-023-01312-2.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"4993186","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Positive Measure of Effective Quasi-Periodic Motion Near a Diophantine Torus","authors":"Abed Bounemoura, Gerard Farré","doi":"10.1007/s00023-023-01302-4","DOIUrl":"10.1007/s00023-023-01302-4","url":null,"abstract":"<div><p>It was conjectured by Herman that an analytic Lagrangian Diophantine quasi-periodic torus <span>({mathcal {T}}_0)</span>, invariant by a real-analytic Hamiltonian system, is always accumulated by a set of positive Lebesgue measure of other Lagrangian Diophantine quasi-periodic invariant tori. While the conjecture is still open, we will prove the following weaker statement: there exists an open set of positive measure (in fact, the relative measure of the complement is exponentially small) around <span>({mathcal {T}}_0)</span> such that the motion of all initial conditions in this set is “effectively” quasi-periodic in the sense that they are close to being quasi-periodic for an interval of time, which is doubly exponentially long with respect to the inverse of the distance to <span>({mathcal {T}}_0)</span>. This open set can be thought of as a neighborhood of a hypothetical invariant set of Lagrangian Diophantine quasi-periodic tori, which may or may not exist.</p></div>","PeriodicalId":463,"journal":{"name":"Annales Henri Poincaré","volume":"24 9","pages":"3289 - 3304"},"PeriodicalIF":1.5,"publicationDate":"2023-04-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s00023-023-01302-4.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"4955803","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}