{"title":"New Correspondences of Integrability Structures and Solution Structures with Miura Transformation","authors":"Qiulan Zhao, Jie Sun, Runliang Lin, Xinyue Li","doi":"10.1016/S0034-4877(26)00053-4","DOIUrl":"10.1016/S0034-4877(26)00053-4","url":null,"abstract":"<div><div>In this paper, the corresponding relationships of the integrability structures and the solution structures between a dispersionless Kadomtsev-Petviashvili (dKP) equation and a dispersionless modified Kadomtsev-Petviashvili (dmKP) equation are obtained. On the one hand, the equivalence of the conservation laws, potential systems, nonlocal conservation laws and extended potential systems for the two equations are explored. On the other hand, starting from the original equations and the extended potential systems, respectively, we establish the correspondences of the solution structures for these two equations. Furthermore, the discrete symmetries of the dmKP equation are presented. It is worth noting that we link the extended potential system with the Type-II hidden symmetry. This combination provides a new perspective for solving the extended potential system. In addition, this method of further studying equations through the Miura transformation can be applied to other equations as well, and it can help us better analyze these equations.</div></div><div>In this paper, the corresponding relationships of the integrability structures and the solution structures between a dispersionless Kadomtsev-Petviashvili (dKP) equation and a dispersionless modified Kadomtsev-Petviashvili (dmKP) equation are obtained. On the one hand, the equivalence of the conservation laws, potential systems, nonlocal conservation laws and extended potential systems for the two equations are explored. On the other hand, starting from the original equations and the extended potential systems, respectively, we establish the correspondences of the solution structures for these two equations. Furthermore, the discrete symmetries of the dmKP equation are presented. It is worth noting that we link the extended potential system with the Type-II hidden symmetry. This combination provides a new perspective for solving the extended potential system. In addition, this method of further studying equations through the Miura transformation can be applied to other equations as well, and it can help us better analyze these equations.</div>","PeriodicalId":49630,"journal":{"name":"Reports on Mathematical Physics","volume":"98 1","pages":"Pages 43-68"},"PeriodicalIF":1.0,"publicationDate":"2026-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148964893","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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":"Superintegrable systems and the N = 2 extended Neveu-Schwarz algebra","authors":"Yanyan Ge, Dafeng Zuo","doi":"10.1016/S0034-4877(26)00054-6","DOIUrl":"10.1016/S0034-4877(26)00054-6","url":null,"abstract":"<div><div>We propose a new infinite-dimensional Lie superalgebra as an extension of the <em>N</em> = 2 Neveu-Schwarz algebra and study its related supersymmetric and local bi-superhamiltonian integrable systems.</div></div><div>We propose a new infinite-dimensional Lie superalgebra as an extension of the <em>N</em> = 2 Neveu-Schwarz algebra and study its related supersymmetric and local bi-superhamiltonian integrable systems.</div>","PeriodicalId":49630,"journal":{"name":"Reports on Mathematical Physics","volume":"98 1","pages":"Pages 69-84"},"PeriodicalIF":1.0,"publicationDate":"2026-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148964894","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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":"The Schrödinger equation with Dirac singular potential","authors":"Michael Maroun","doi":"10.1016/S0034-4877(26)00055-8","DOIUrl":"10.1016/S0034-4877(26)00055-8","url":null,"abstract":"<div><div>A framework is presented to solve partial differential equations (PDE) defined through a generalization of pseudo-differential operators, when the psi-DO symbol takes on coefficient functions that are singular distributions. Such treatments of PDE have not been treated systematically elsewhere. The result is a rigorous mathematical method, which does not rely upon renormalization or regularization, while producing bound state energy results in agreement with the literature. The procedure is the same in each dimension. So there is no ad hoc dimensional regularization. The method also does not rely upon self-adjoint extensions (SAEs) of the Laplace operator. This is important for non-Schrödinger systems, like the Dirac equation, where the kinetic energy is not prescribed by the Laplace operator. It is also a necessary property of any rigorous mathematical form of relativistic quantum field theories. SAEs only exist in dimensions less than four, whereas the method presented is unaffected by the number of dimensions. This new framework is applied to the Schrödinger equation in dimensions one, two, and three, for comparison with the method of SAEs. A precise definition of hyperlocal interaction is introduced, which provides a nonperturbative method for handling singular potentials. Lastly, a rigorous distributional version of the Hellmann-Feynman theorem is shown.</div></div><div>A framework is presented to solve partial differential equations (PDE) defined through a generalization of pseudo-differential operators, when the psi-DO symbol takes on coefficient functions that are singular distributions. Such treatments of PDE have not been treated systematically elsewhere. The result is a rigorous mathematical method, which does not rely upon renormalization or regularization, while producing bound state energy results in agreement with the literature. The procedure is the same in each dimension. So there is no ad hoc dimensional regularization. The method also does not rely upon self-adjoint extensions (SAEs) of the Laplace operator. This is important for non-Schrödinger systems, like the Dirac equation, where the kinetic energy is not prescribed by the Laplace operator. It is also a necessary property of any rigorous mathematical form of relativistic quantum field theories. SAEs only exist in dimensions less than four, whereas the method presented is unaffected by the number of dimensions. This new framework is applied to the Schrödinger equation in dimensions one, two, and three, for comparison with the method of SAEs. A precise definition of hyperlocal interaction is introduced, which provides a nonperturbative method for handling singular potentials. Lastly, a rigorous distributional version of the Hellmann-Feynman theorem is shown.</div>","PeriodicalId":49630,"journal":{"name":"Reports on Mathematical Physics","volume":"98 1","pages":"Pages 85-130"},"PeriodicalIF":1.0,"publicationDate":"2026-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148964895","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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":"Adjointness of generalized Sasaki operations in posets","authors":"Ivan Chajda, Helmut Länger","doi":"10.1016/S0034-4877(26)00050-9","DOIUrl":"10.1016/S0034-4877(26)00050-9","url":null,"abstract":"<div><div>The Sasaki projection and its dual were introduced as mappings from the lattice of closed subspaces of a Hilbert space onto one of its segments. It was shown implicitly in [<span><span>6</span></span>] and in detail in [<span><span>3</span></span>] that the Sasaki projection and its dual form an adjoint pair in every orthomodular lattice. Later on the authors described large classes of algebras in which Sasaki operations can be defined and form an adjoint pair. The aim of the present paper is to extend these investigations to bounded posets with a unary operation. We introduce the so-called generalized Sasaki projection and its dual as well as the so-called generalized Sasaki operations induced by them. When treating these projections and operations we consider only so-called saturated posets, i.e. posets having the property that above any lower bound of two elements there is at least one maximal lower bound and below any upper bound of two elements there is at least one minimal upper bound. We prove that the generalized Sasaki operations are well defined if and only if the poset in question is orthogonal. We characterize adjointness of the generalized Sasaki operations in different ways and show that adjointness is possible only if the unary operation is a complementation. Finally, we prove that in every saturated orthomodular poset the generalized Sasaki operations form an adjoint pair.</div></div><div>The Sasaki projection and its dual were introduced as mappings from the lattice of closed subspaces of a Hilbert space onto one of its segments. It was shown implicitly in [<span><span>6</span></span>] and in detail in [<span><span>3</span></span>] that the Sasaki projection and its dual form an adjoint pair in every orthomodular lattice. Later on the authors described large classes of algebras in which Sasaki operations can be defined and form an adjoint pair. The aim of the present paper is to extend these investigations to bounded posets with a unary operation. We introduce the so-called generalized Sasaki projection and its dual as well as the so-called generalized Sasaki operations induced by them. When treating these projections and operations we consider only so-called saturated posets, i.e. posets having the property that above any lower bound of two elements there is at least one maximal lower bound and below any upper bound of two elements there is at least one minimal upper bound. We prove that the generalized Sasaki operations are well defined if and only if the poset in question is orthogonal. We characterize adjointness of the generalized Sasaki operations in different ways and show that adjointness is possible only if the unary operation is a complementation. Finally, we prove that in every saturated orthomodular poset the generalized Sasaki operations form an adjoint pair.</div>","PeriodicalId":49630,"journal":{"name":"Reports on Mathematical Physics","volume":"98 1","pages":"Pages 1-12"},"PeriodicalIF":1.0,"publicationDate":"2026-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148964833","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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":"Gray's decomposition of generalized quasi-Einstein spacetimes in the sense of Chaki with semisymmetric w-recurrent metric connections","authors":"Samrat Hossain, Avijit Sarkar","doi":"10.1016/S0034-4877(26)00051-0","DOIUrl":"10.1016/S0034-4877(26)00051-0","url":null,"abstract":"<div><div>In the present article, we investigate generalized quasi-Einstein spacetimes in the sense of Chaki with its Ricci curvature belonging to Gray's decomposition subspaces equipped with semisymmetric metric connections. Generalized Robertson-Walker spacetimes are also considered. It is established that a generalized quasi-Einstein spacetime with its Ricci curvature belonging to any Gray's decomposition subspace becomes perfect fluid spacetime under some restrictions. Further, it is established that a generalized quasi-Einstein generalized Robertson-Walker spacetime is also a perfect fluid spacetime.</div></div><div>In the present article, we investigate generalized quasi-Einstein spacetimes in the sense of Chaki with its Ricci curvature belonging to Gray's decomposition subspaces equipped with semisymmetric metric connections. Generalized Robertson-Walker spacetimes are also considered. It is established that a generalized quasi-Einstein spacetime with its Ricci curvature belonging to any Gray's decomposition subspace becomes perfect fluid spacetime under some restrictions. Further, it is established that a generalized quasi-Einstein generalized Robertson-Walker spacetime is also a perfect fluid spacetime.</div>","PeriodicalId":49630,"journal":{"name":"Reports on Mathematical Physics","volume":"98 1","pages":"Pages 13-27"},"PeriodicalIF":1.0,"publicationDate":"2026-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148964827","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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":"The Multidimensional Thermoelastic System with Variable Coefficients and Wentzell Boundary Conditions: Uniform Stability","authors":"Remissa Boureghida, Hicham Kasri","doi":"10.1016/S0034-4877(26)00041-8","DOIUrl":"10.1016/S0034-4877(26)00041-8","url":null,"abstract":"<div><div>In this paper, we consider a variable-coefficient linear thermoelastic system with interior localized damping and dynamic Wentzell boundary conditions with delay. The model describes the interaction between the mechanical displacement <em>u</em> and temperature θ, and is subject to dynamic Wentzell-type boundary conditions. Our main result demonstrates that this internal damping, localized on a subset ω ⊂ Ω, where <em>a(x)</em> ≥ a<sub>0</sub> > 0 over ω ⊂ Ω, is sufficient to achieve exponential stabilization of the entire system. To establish the well-posedness of the system, we apply semigroup theory. Then, by combining the multiplier method and the Riemannian geometry approach, we derive suitable energy estimates and prove the exponential decay of energy. The stability result highlights the interplay between interior damping, boundary feedback, and the delay term, and provides a meaningful extension of existing stabilization results for thermoelastic systems.</div></div><div>In this paper, we consider a variable-coefficient linear thermoelastic system with interior localized damping and dynamic Wentzell boundary conditions with delay. The model describes the interaction between the mechanical displacement <em>u</em> and temperature θ, and is subject to dynamic Wentzell-type boundary conditions. Our main result demonstrates that this internal damping, localized on a subset ω ⊂ Ω, where <em>a(x)</em> ≥ a<sub>0</sub> > 0 over ω ⊂ Ω, is sufficient to achieve exponential stabilization of the entire system. To establish the well-posedness of the system, we apply semigroup theory. Then, by combining the multiplier method and the Riemannian geometry approach, we derive suitable energy estimates and prove the exponential decay of energy. The stability result highlights the interplay between interior damping, boundary feedback, and the delay term, and provides a meaningful extension of existing stabilization results for thermoelastic systems.</div>","PeriodicalId":49630,"journal":{"name":"Reports on Mathematical Physics","volume":"97 3","pages":"Pages 379-405"},"PeriodicalIF":1.0,"publicationDate":"2026-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148571862","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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":"BPS Skyrme Models and Contact Geometry","authors":"R. Slobodeanu, J.M. Speight","doi":"10.1016/S0034-4877(26)00037-6","DOIUrl":"10.1016/S0034-4877(26)00037-6","url":null,"abstract":"<div><div>A Skyrme-type energy functional for maps \u0000\t\t\t\t<span><math><mi>φ</mi><mo>:</mo><mi>M</mi><mo>→</mo><mi>N</mi></math></span> from an oriented Riemannian 3-manifold <em>M</em> to a contact 3-manifold <em>N</em> is defined, generalizing the Bogomol’nyi-Pra-sad-Sommerfeld (BPS) Skyrme energy of Ferreira and Zakrzewski. This energy has a topological lower bound, attained by solutions of a first-order self-duality equation which we call (strong) Beltrami maps. In the case where <em>N</em> is the 3 -sphere, we show that the original Ferreira-Zakrzewski model (which has \u0000\t\t\t\t<span><math><mi>N</mi><mo>=</mo><msup><mrow><mi>S</mi></mrow><mrow><mn>3</mn></mrow></msup></math></span> with the standard contact structure) can have no BPS solutions on \u0000\t\t\t\t<span><math><mi>M</mi><mo>=</mo><msup><mrow><mi>S</mi></mrow><mrow><mn>3</mn></mrow></msup></math></span> with \u0000\t\t\t\t<span><math><mrow><mo>|</mo></mrow><mi>deg</mi><mo></mo><mo>(</mo><mi>φ</mi><mo>)</mo><mrow><mo>|</mo></mrow><mo>></mo><mn>1</mn></math></span> if the coupling constant has the lowest admissible value.</div></div><div>A Skyrme-type energy functional for maps \u0000\t\t\t\t<span><math><mi>φ</mi><mo>:</mo><mi>M</mi><mo>→</mo><mi>N</mi></math></span> from an oriented Riemannian 3-manifold <em>M</em> to a contact 3-manifold <em>N</em> is defined, generalizing the Bogomol’nyi-Pra-sad-Sommerfeld (BPS) Skyrme energy of Ferreira and Zakrzewski. This energy has a topological lower bound, attained by solutions of a first-order self-duality equation which we call (strong) Beltrami maps. In the case where <em>N</em> is the 3 -sphere, we show that the original Ferreira-Zakrzewski model (which has \u0000\t\t\t\t<span><math><mi>N</mi><mo>=</mo><msup><mrow><mi>S</mi></mrow><mrow><mn>3</mn></mrow></msup></math></span> with the standard contact structure) can have no BPS solutions on \u0000\t\t\t\t<span><math><mi>M</mi><mo>=</mo><msup><mrow><mi>S</mi></mrow><mrow><mn>3</mn></mrow></msup></math></span> with \u0000\t\t\t\t<span><math><mrow><mo>|</mo></mrow><mi>deg</mi><mo></mo><mo>(</mo><mi>φ</mi><mo>)</mo><mrow><mo>|</mo></mrow><mo>></mo><mn>1</mn></math></span> if the coupling constant has the lowest admissible value.</div>","PeriodicalId":49630,"journal":{"name":"Reports on Mathematical Physics","volume":"97 3","pages":"Pages 303-317"},"PeriodicalIF":1.0,"publicationDate":"2026-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148365810","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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":"Lattice Paths and Quiver Generating Series with Higher Level Generators","authors":"Dušan Đorđević, Marko Stošić","doi":"10.1016/S0034-4877(26)00039-X","DOIUrl":"10.1016/S0034-4877(26)00039-X","url":null,"abstract":"<div><div>The generalized knots-quivers correspondence extends the original knots-quivers correspondence by allowing higher level generators of quiver generating series. In this paper we explore the underlying combinatorics of such generating series, relationship with the Bogo-mol'nyi-Prasad-Sommerfield (BPS) numbers of a corresponding knot, and new combinatorial interpretations of the coefficients of generating series in terms of the count of lattice paths.</div></div><div>The generalized knots-quivers correspondence extends the original knots-quivers correspondence by allowing higher level generators of quiver generating series. In this paper we explore the underlying combinatorics of such generating series, relationship with the Bogo-mol'nyi-Prasad-Sommerfield (BPS) numbers of a corresponding knot, and new combinatorial interpretations of the coefficients of generating series in terms of the count of lattice paths.</div>","PeriodicalId":49630,"journal":{"name":"Reports on Mathematical Physics","volume":"97 3","pages":"Pages 333-351"},"PeriodicalIF":1.0,"publicationDate":"2026-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148365814","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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":"Fractional-Order Regularization of Quantum Vacuum Energy Via The Mittag-Leffler Function","authors":"Arturo Tozzi","doi":"10.1016/S0034-4877(26)00038-8","DOIUrl":"10.1016/S0034-4877(26)00038-8","url":null,"abstract":"<div><div>The challenge of the vacuum catastrophe arises from the discrepancy between quantum field theoretical predictions and the observed vacuum energy density. Using analytic continuation techniques and asymptotic analysis to ensure physical consistency, we explored the Mittag-Leffler function (MLF), a generalized exponential function applied in fractional calculus and anomalous diffusion, as a potential framework to address the vacuum catastrophe. We computed the MLFregularized vacuum energy integral, evaluated renormalization group equations, derived modified field equations for different parameter choices and provided numerical solutions of the modified Friedmann equations to track the evolution of the scale factor. Unlike conventional approaches relying on arbitrary cutoffs and standard QFT predictions, which exhibit uncontrolled growth at high energies, MLF regulates coupling divergences by attenuating high-energy contributions while preserving Lorentz invariance and renormalization group consistency. The field propagation profile exhibited suppression of high-energy components, consistent with modified dispersion relations predicted by fractional-order formulations. The scale factor evolution indicated a reduced contribution from vacuum energy, aligning with the expectation that MLF diminishes the effective cosmological constant over cosmic timescales. We found minimal deviations in the cosmic microwave background power spectrum relative to the standard cosmological model, consistent with current observational constraints.</div></div><div>The challenge of the vacuum catastrophe arises from the discrepancy between quantum field theoretical predictions and the observed vacuum energy density. Using analytic continuation techniques and asymptotic analysis to ensure physical consistency, we explored the Mittag-Leffler function (MLF), a generalized exponential function applied in fractional calculus and anomalous diffusion, as a potential framework to address the vacuum catastrophe. We computed the MLFregularized vacuum energy integral, evaluated renormalization group equations, derived modified field equations for different parameter choices and provided numerical solutions of the modified Friedmann equations to track the evolution of the scale factor. Unlike conventional approaches relying on arbitrary cutoffs and standard QFT predictions, which exhibit uncontrolled growth at high energies, MLF regulates coupling divergences by attenuating high-energy contributions while preserving Lorentz invariance and renormalization group consistency. The field propagation profile exhibited suppression of high-energy components, consistent with modified dispersion relations predicted by fractional-order formulations. The scale factor evolution indicated a reduced contribution from vacuum energy, aligning with the expectation that MLF diminishes the effective cosmological constant over cosmic timescales. We found minimal deviations in the cosmic microwav","PeriodicalId":49630,"journal":{"name":"Reports on Mathematical Physics","volume":"97 3","pages":"Pages 319-331"},"PeriodicalIF":1.0,"publicationDate":"2026-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148365813","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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}