Pub Date : 2026-01-29DOI: 10.1016/j.aop.2026.170364
Ahmed Farag Ali
<div><div>Motivated by Maldacena’s observer-centric formulation of de Sitter physics (Maldacena, 2024), we develop an observer-dependent state-counting framework in Euclidean de Sitter space by modeling the observer as a massive equatorial worldline carrying an SU(3) clock. Starting from the gauge-fixed graviton path integral on <span><math><msup><mrow><mi>S</mi></mrow><mrow><mi>D</mi></mrow></msup></math></span>, we trace the one-loop phase <span><math><msup><mrow><mi>i</mi></mrow><mrow><mi>D</mi><mo>+</mo><mn>2</mn></mrow></msup></math></span> to a finite set of scalar and conformal Killing modes and show that, once the worldline is included, the <span><math><mrow><mo>(</mo><mi>D</mi><mo>−</mo><mn>1</mn><mo>)</mo></mrow></math></span> transverse negative modes cancel the corresponding <span><math><mrow><mo>(</mo><mi>D</mi><mo>−</mo><mn>1</mn><mo>)</mo></mrow></math></span> conformal Killing directions mode by mode. The residual fixed-<span><math><mi>β</mi></math></span> phase from the global conformal factor and reparametrizations is removed by imposing the Hamiltonian constraint <span><math><mrow><msub><mrow><mi>H</mi></mrow><mrow><mtext>patch</mtext></mrow></msub><mo>−</mo><msub><mrow><mi>H</mi></mrow><mrow><mtext>clock</mtext></mrow></msub><mo>−</mo><mi>ν</mi><mo>=</mo><mn>0</mn></mrow></math></span> via a Bromwich inverse Laplace transform, which under explicit complete-monotonicity assumptions yields a real and positive microcanonical density. We stress that this positivity statement is conditional on Assumptions (A1)–(A3) and is established at one loop about the round <span><math><msup><mrow><mi>S</mi></mrow><mrow><mi>D</mi></mrow></msup></math></span> saddle in the probe regime <span><math><mrow><mi>G</mi><msub><mrow><mi>E</mi></mrow><mrow><mi>clock</mi></mrow></msub><mo>/</mo><mi>R</mi><mo>≪</mo><mn>1</mn></mrow></math></span>; a self-consistent backreacting or higher-loop extension is a natural next step. In earlier work (Ali and Ali 2025; Ali 2025) we argued that unbroken SU(3) confinement at <span><math><mrow><mi>T</mi><mo>→</mo><mn>0</mn></mrow></math></span> can account for the observed value of the cosmological constant and for the origin of the fundamental constants <span><math><mrow><mo>(</mo><mo>ħ</mo><mo>,</mo><mi>G</mi><mo>,</mo><mi>c</mi><mo>)</mo></mrow></math></span> as effective couplings fixed by the SU(3) vacuum structure; this makes SU(3) the natural candidate for the internal clock of de Sitter, whose radius and temperature are themselves set by the same cosmological constant. Here that idea is implemented with three explicit SU(3) realizations (qutrit, Cartan weight-lattice, and <span><math><mrow><mi>U</mi><msup><mrow><mrow><mo>(</mo><mn>1</mn><mo>)</mo></mrow></mrow><mrow><mn>2</mn></mrow></msup></mrow></math></span> rotor), for which the observer-inclusive density of states factorizes into a universal gravity factor, a universal worldline residue, and a clock-dependent SU(3) weight.</div><div><strong>Summary of con
受Maldacena以观察者为中心的德西特物理公式（Maldacena, 2024）的启发，我们通过将观察者建模为携带SU(3)时钟的巨大赤道世界线，在欧几里得德西特空间中开发了一个依赖观察者的状态计数框架。从SD上的规定引力子路径积分出发，我们将单环相位iD+2追踪到标量和共形杀戮模式的有限集合，并证明，一旦世界线被包括在内，（D−1）横向负模一个接一个地抵消了相应的（D−1）共形杀戮方向。通过施加哈密顿约束Hpatch - Hclock - ν=0，通过Bromwich逆变换去除全局共形因子和再参数化的残差固定β相位，该约束在显式完全单调性假设下产生实正微正则密度。我们强调，这种积极的陈述是以假设(A1) - (A3)为条件的，并且是在探测区圆形SD鞍形的一个环路上建立起来的。自一致的反向反应或高循环扩展是自然而然的下一步。在早期的工作（Ali and Ali 2025; Ali 2025）中，我们认为T→0时的不间断SU(3)约束可以解释宇宙学常数的观测值和基本常数（η，G,c）的起源，它们是由SU(3)真空结构固定的有效耦合；这使得SU(3)成为德西特内部时钟的自然候选者，其半径和温度本身是由相同的宇宙常数设定的。在这里，这个想法是通过三种显式SU(3)实现（qutrit， Cartan权重晶格和U(1)2转子）来实现的，其中包含观察者的状态密度被分解为一个万有引力因子，一个万有引力世界线残差和一个依赖时钟的SU(3)权重。捐款摘要。(i)用（D−1）横向n=0世界线模确定（D−1）赤道移动共形消杀方向，给出一个模对模的准单回路相位消去；（ii）世界线决定因素的双重评估（残余/热核提取和Gel 'fand-Yaglom检查）；（iii）三个SU(3)时钟模型的封闭形式配分函数。微正则密度的现实性和非负性取决于第7节中的显式谱假设(A1) - (A3)，包括β0=2π附近条的可解析性和相位剥离斑块配分函数的完全单调性。
{"title":"Relational de Sitter state counting with an SU(3) clock","authors":"Ahmed Farag Ali","doi":"10.1016/j.aop.2026.170364","DOIUrl":"10.1016/j.aop.2026.170364","url":null,"abstract":"<div><div>Motivated by Maldacena’s observer-centric formulation of de Sitter physics (Maldacena, 2024), we develop an observer-dependent state-counting framework in Euclidean de Sitter space by modeling the observer as a massive equatorial worldline carrying an SU(3) clock. Starting from the gauge-fixed graviton path integral on <span><math><msup><mrow><mi>S</mi></mrow><mrow><mi>D</mi></mrow></msup></math></span>, we trace the one-loop phase <span><math><msup><mrow><mi>i</mi></mrow><mrow><mi>D</mi><mo>+</mo><mn>2</mn></mrow></msup></math></span> to a finite set of scalar and conformal Killing modes and show that, once the worldline is included, the <span><math><mrow><mo>(</mo><mi>D</mi><mo>−</mo><mn>1</mn><mo>)</mo></mrow></math></span> transverse negative modes cancel the corresponding <span><math><mrow><mo>(</mo><mi>D</mi><mo>−</mo><mn>1</mn><mo>)</mo></mrow></math></span> conformal Killing directions mode by mode. The residual fixed-<span><math><mi>β</mi></math></span> phase from the global conformal factor and reparametrizations is removed by imposing the Hamiltonian constraint <span><math><mrow><msub><mrow><mi>H</mi></mrow><mrow><mtext>patch</mtext></mrow></msub><mo>−</mo><msub><mrow><mi>H</mi></mrow><mrow><mtext>clock</mtext></mrow></msub><mo>−</mo><mi>ν</mi><mo>=</mo><mn>0</mn></mrow></math></span> via a Bromwich inverse Laplace transform, which under explicit complete-monotonicity assumptions yields a real and positive microcanonical density. We stress that this positivity statement is conditional on Assumptions (A1)–(A3) and is established at one loop about the round <span><math><msup><mrow><mi>S</mi></mrow><mrow><mi>D</mi></mrow></msup></math></span> saddle in the probe regime <span><math><mrow><mi>G</mi><msub><mrow><mi>E</mi></mrow><mrow><mi>clock</mi></mrow></msub><mo>/</mo><mi>R</mi><mo>≪</mo><mn>1</mn></mrow></math></span>; a self-consistent backreacting or higher-loop extension is a natural next step. In earlier work (Ali and Ali 2025; Ali 2025) we argued that unbroken SU(3) confinement at <span><math><mrow><mi>T</mi><mo>→</mo><mn>0</mn></mrow></math></span> can account for the observed value of the cosmological constant and for the origin of the fundamental constants <span><math><mrow><mo>(</mo><mo>ħ</mo><mo>,</mo><mi>G</mi><mo>,</mo><mi>c</mi><mo>)</mo></mrow></math></span> as effective couplings fixed by the SU(3) vacuum structure; this makes SU(3) the natural candidate for the internal clock of de Sitter, whose radius and temperature are themselves set by the same cosmological constant. Here that idea is implemented with three explicit SU(3) realizations (qutrit, Cartan weight-lattice, and <span><math><mrow><mi>U</mi><msup><mrow><mrow><mo>(</mo><mn>1</mn><mo>)</mo></mrow></mrow><mrow><mn>2</mn></mrow></msup></mrow></math></span> rotor), for which the observer-inclusive density of states factorizes into a universal gravity factor, a universal worldline residue, and a clock-dependent SU(3) weight.</div><div><strong>Summary of con","PeriodicalId":8249,"journal":{"name":"Annals of Physics","volume":"487 ","pages":"Article 170364"},"PeriodicalIF":3.0,"publicationDate":"2026-01-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146075999","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}
Pub Date : 2026-01-29DOI: 10.1016/j.aop.2026.170368
Pushpendra Singh
This work reformulates quantum mechanics in real Hilbert space and demonstrates that the complex structure inherent to the Schrödinger equation can be fully captured by a coupled system of real-valued dynamics. By employing the standard field isomorphism of to , the real counterpart of the Schrödinger equation is derived, yielding a system of coupled real partial differential equations. This system reveals a symplectic structure where the symplectic matrix geometrically represents the imaginary unit , acting as a phase-space rotation operator. Time-independent solutions decouple into identical real Helmholtz equations, preserving spectral equivalence. The reformulation provides geometric insights into foundational aspects: the geometric representation of , the emergence of probability conservation from real-component interactions, and the encoding of quantum phase relationships through the multiplicative structure of the field. This perspective reinforces connections to classical Hamiltonian mechanics and geometric quantization, suggesting that complex numbers are structural, emerging from field operations on the real plane, rather than fundamental. Building on these foundations, we present original results where quantum computation elements like qubits and gates are shown to have equivalent representations as real symplectic and special orthogonal matrices, maintaining unitary equivalence. We introduce a framework for quantum computation within a real vector space and provide a generalized protocol for generating entangled Bell states. These results offer a new perspective on the necessity of complex numbers in quantum theory, providing a framework with potential computational advantages for hybrid quantum–classical systems and enhanced geometric interpretability.
{"title":"Quantum dynamics in real Hilbert space: Algebraic isomorphism and symplectic geometry of the Schrödinger equation","authors":"Pushpendra Singh","doi":"10.1016/j.aop.2026.170368","DOIUrl":"10.1016/j.aop.2026.170368","url":null,"abstract":"<div><div>This work reformulates quantum mechanics in real Hilbert space and demonstrates that the complex structure inherent to the Schrödinger equation can be fully captured by a coupled system of real-valued dynamics. By employing the standard field isomorphism of <span><math><mrow><mo>(</mo><msup><mrow><mi>R</mi></mrow><mrow><mn>2</mn></mrow></msup><mo>,</mo><mo>+</mo><mo>,</mo><mi>⋅</mi><mo>)</mo></mrow></math></span> to <span><math><mi>ℂ</mi></math></span>, the real counterpart of the Schrödinger equation is derived, yielding a system of coupled real partial differential equations. This system reveals a symplectic structure where the symplectic matrix <span><math><mi>J</mi></math></span> geometrically represents the imaginary unit <span><math><mi>i</mi></math></span>, acting as a phase-space rotation operator. Time-independent solutions decouple into identical real Helmholtz equations, preserving spectral equivalence. The reformulation provides geometric insights into foundational aspects: the geometric representation of <span><math><mi>i</mi></math></span>, the emergence of probability conservation from real-component interactions, and the encoding of quantum phase relationships through the multiplicative structure of the <span><math><msup><mrow><mi>R</mi></mrow><mrow><mn>2</mn></mrow></msup></math></span> field. This perspective reinforces connections to classical Hamiltonian mechanics and geometric quantization, suggesting that complex numbers are structural, emerging from field operations on the real plane, rather than fundamental. Building on these foundations, we present original results where quantum computation elements like qubits and gates are shown to have equivalent representations as real symplectic and special orthogonal matrices, maintaining unitary equivalence. We introduce a framework for quantum computation within a real vector space and provide a generalized protocol for generating entangled Bell states. These results offer a new perspective on the necessity of complex numbers in quantum theory, providing a framework with potential computational advantages for hybrid quantum–classical systems and enhanced geometric interpretability.</div></div>","PeriodicalId":8249,"journal":{"name":"Annals of Physics","volume":"487 ","pages":"Article 170368"},"PeriodicalIF":3.0,"publicationDate":"2026-01-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146076061","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}
Pub Date : 2026-01-29DOI: 10.1016/j.aop.2026.170367
Bilal Canturk
The time evolution of the one-point probability vector of stochastic processes and quantum processes for -level systems have been unified. Hence, quantum states and quantum operations can be regarded as generalizations of the one-point probability vectors and stochastic matrices, respectively. More essentially, based on the unification, it has been proven that completely positive divisibility (CP-divisibility) for quantum operations is the natural extension of the Chapman–Kolmogorov equation. It is thus shown that CP-divisibility is a necessary but insufficient condition for a quantum process to be specified as Markovian. The main results have been illustrated through a dichotomic Markov process.
{"title":"Unification of stochastic matrices and quantum operations for N-level systems","authors":"Bilal Canturk","doi":"10.1016/j.aop.2026.170367","DOIUrl":"10.1016/j.aop.2026.170367","url":null,"abstract":"<div><div>The time evolution of the one-point probability vector of stochastic processes and quantum processes for <span><math><mi>N</mi></math></span>-level systems have been unified. Hence, quantum states and quantum operations can be regarded as generalizations of the one-point probability vectors and stochastic matrices, respectively. More essentially, based on the unification, it has been proven that completely positive divisibility (CP-divisibility) for quantum operations is the natural extension of the Chapman–Kolmogorov equation. It is thus shown that CP-divisibility is a necessary but insufficient condition for a quantum process to be specified as Markovian. The main results have been illustrated through a dichotomic Markov process.</div></div>","PeriodicalId":8249,"journal":{"name":"Annals of Physics","volume":"487 ","pages":"Article 170367"},"PeriodicalIF":3.0,"publicationDate":"2026-01-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146076059","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}
Pub Date : 2026-01-28DOI: 10.1016/j.aop.2026.170365
S. Bondarenko, Raghvendra Singh
We analyze finite-volume, spatially open FLRW spacetime(s) in the time-dependent thermodynamic limit, where the physical volume depends on the number of particles in it and the particle density function . This prescription makes the boundary a dynamical element and modifies the Friedmann sector through a single combination of the time derivatives of the particle number and the density function. This function accounts for possible thermodynamic and/or quantum changes the system undergoes, and we solve the corresponding FLRW equations written in terms of this function for the proposed finite volume FLRW geometries and different equations of state of the particles. Correspondingly, we present exact trigonometric and hyperbolic solution families on both positive- and negative-energy branches and summarize their kinematic properties. Using an exact reorganization of the Friedmann equation and introducing an effective expansion rate of the volume, a new term similar to a cosmological constant in the equations arises in the framework without adding new fields. The approach also predicts a small, testable correction to observed redshifts sourced by boundary motion. Throughout, the connection between the thermodynamic inputs, which are particle number and density function, and between the background evolution of the open FLRW geometry is kept explicit.
{"title":"Open FLRW spacetime in a time-dependent thermodynamic limit","authors":"S. Bondarenko, Raghvendra Singh","doi":"10.1016/j.aop.2026.170365","DOIUrl":"10.1016/j.aop.2026.170365","url":null,"abstract":"<div><div>We analyze finite-volume, spatially open <span><math><mrow><mo>(</mo><mi>κ</mi><mo>=</mo><mo>−</mo><mn>1</mn><mo>)</mo></mrow></math></span> FLRW spacetime(s) in the time-dependent thermodynamic limit, where the physical volume depends on the number of particles <span><math><mrow><mi>N</mi><mrow><mo>(</mo><mi>t</mi><mo>)</mo></mrow></mrow></math></span> in it and the particle density function <span><math><mrow><msup><mrow><mi>γ</mi></mrow><mrow><mo>−</mo><mn>3</mn></mrow></msup><mrow><mo>(</mo><mi>t</mi><mo>,</mo><mi>T</mi><mo>)</mo></mrow></mrow></math></span>. This prescription makes the boundary a dynamical element and modifies the Friedmann sector through a single combination of the time derivatives of the particle number and the density function. This function accounts for possible thermodynamic and/or quantum changes the system undergoes, and we solve the corresponding FLRW equations written in terms of this function for the proposed finite volume FLRW geometries and different equations of state of the particles. Correspondingly, we present exact trigonometric and hyperbolic solution families on both positive- and negative-energy branches and summarize their kinematic properties. Using an exact reorganization of the Friedmann equation and introducing an effective expansion rate of the volume, a new term similar to a cosmological constant in the equations arises in the framework without adding new fields. The approach also predicts a small, testable correction to observed redshifts sourced by boundary motion. Throughout, the connection between the thermodynamic inputs, which are particle number and density function, and between the background evolution of the open FLRW geometry is kept explicit.</div></div>","PeriodicalId":8249,"journal":{"name":"Annals of Physics","volume":"487 ","pages":"Article 170365"},"PeriodicalIF":3.0,"publicationDate":"2026-01-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146076058","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}
Pub Date : 2026-01-27DOI: 10.1016/j.aop.2026.170353
Zachary P. Bradshaw, Jeffrey J. Dale, Ethan N. Evans
We give an introduction to the theory of quantum error correction using stabilizer codes that is geared towards the working computer scientists and mathematicians with an interest in exploring this area. To this end, we begin with an introduction to basic quantum computation for the uninitiated. We then construct several examples of simple error correcting codes without reference to the underlying mathematical formalism in order to develop the readers intuition for the structure of a generic code. With this in hand, we then discuss the more general theory of stabilizer codes and provide the necessary level of mathematical detail for the non-mathematician. Finally, we give a brief look at the elegant homological algebra formulation for topological codes. As a bonus, we give implementations of the codes we mention using OpenQASM, and we address the more recent approaches to decoding using neural networks. We do not attempt to give a complete overview of the entire field, but provide the reader with the level of detail needed to continue in this direction.
{"title":"Introduction to quantum error correction with stabilizer codes","authors":"Zachary P. Bradshaw, Jeffrey J. Dale, Ethan N. Evans","doi":"10.1016/j.aop.2026.170353","DOIUrl":"10.1016/j.aop.2026.170353","url":null,"abstract":"<div><div>We give an introduction to the theory of quantum error correction using stabilizer codes that is geared towards the working computer scientists and mathematicians with an interest in exploring this area. To this end, we begin with an introduction to basic quantum computation for the uninitiated. We then construct several examples of simple error correcting codes without reference to the underlying mathematical formalism in order to develop the readers intuition for the structure of a generic code. With this in hand, we then discuss the more general theory of stabilizer codes and provide the necessary level of mathematical detail for the non-mathematician. Finally, we give a brief look at the elegant homological algebra formulation for topological codes. As a bonus, we give implementations of the codes we mention using OpenQASM, and we address the more recent approaches to decoding using neural networks. We do not attempt to give a complete overview of the entire field, but provide the reader with the level of detail needed to continue in this direction.</div></div>","PeriodicalId":8249,"journal":{"name":"Annals of Physics","volume":"487 ","pages":"Article 170353"},"PeriodicalIF":3.0,"publicationDate":"2026-01-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146076062","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}
Pub Date : 2026-01-23DOI: 10.1016/j.aop.2026.170362
Tarun Advaith Kumar , Leon Balents , Timothy H. Hsieh , Roger G. Melko
A variety of generative neural networks recently adopted from machine learning have provided promising strategies for studying quantum matter. In particular, the success of autoregressive models in natural language processing has motivated their use as variational ansätze, with the hope that their demonstrated ability to scale will transfer to simulations of quantum many-body systems. In this paper, we introduce an autoregressive framework to calculate finite-temperature properties of a quantum system based on the imaginary-time evolution of an ensemble of pure states. We find that established approaches based on minimally entangled typical thermal states (METTS) have numerical instabilities when an autoregressive recurrent neural network is used as the variational ansätz. We show that these instabilities can be mitigated by evolving the initial ensemble states with a unitary operation, along with applying a threshold to curb runaway evolution of ensemble members. By comparing our algorithm to exact results for the spin 1/2 quantum XY chain, we demonstrate that autoregressive typical thermal states are capable of accurately calculating thermal observables.
{"title":"Autoregressive typical thermal states","authors":"Tarun Advaith Kumar , Leon Balents , Timothy H. Hsieh , Roger G. Melko","doi":"10.1016/j.aop.2026.170362","DOIUrl":"10.1016/j.aop.2026.170362","url":null,"abstract":"<div><div>A variety of generative neural networks recently adopted from machine learning have provided promising strategies for studying quantum matter. In particular, the success of autoregressive models in natural language processing has motivated their use as variational ansätze, with the hope that their demonstrated ability to scale will transfer to simulations of quantum many-body systems. In this paper, we introduce an autoregressive framework to calculate finite-temperature properties of a quantum system based on the imaginary-time evolution of an ensemble of pure states. We find that established approaches based on minimally entangled typical thermal states (METTS) have numerical instabilities when an autoregressive recurrent neural network is used as the variational ansätz. We show that these instabilities can be mitigated by evolving the initial ensemble states with a unitary operation, along with applying a threshold to curb runaway evolution of ensemble members. By comparing our algorithm to exact results for the spin 1/2 quantum XY chain, we demonstrate that autoregressive typical thermal states are capable of accurately calculating thermal observables.</div></div>","PeriodicalId":8249,"journal":{"name":"Annals of Physics","volume":"487 ","pages":"Article 170362"},"PeriodicalIF":3.0,"publicationDate":"2026-01-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146076060","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}
Pub Date : 2026-01-23DOI: 10.1016/j.aop.2026.170360
Bekir Can Lütfüoğlu , Erdinç Ulaş Saka , Abubakir Shermatov , Javlon Rayimbaev , Inomjon Ibragimov , Sokhibjan Muminov
We investigate gravitational quasinormal modes of the Dymnikova black hole, a regular spacetime in which the central singularity is replaced by a de Sitter core. This geometry, originally proposed as a phenomenological model, also arises naturally in the framework of Asymptotically Safe gravity, where quantum corrections lead to a scale-dependent modification of the Schwarzschild solution. Focusing on axial gravitational perturbations, we compute the dominant quasinormal frequencies using the WKB method with Padé approximants and verify the results with time-domain integration. We find that the introduction of the quantum parameter leads to systematic deviations from the Schwarzschild spectrum: the real oscillation frequency decreases as increases, while the damping rate also becomes smaller, implying longer-lived modes. In the limit of large , the quasinormal spectrum smoothly approaches the Schwarzschild case. These results suggest that even though the corrections are localized near the horizon, they leave imprints in the gravitational-wave ringdown which may become accessible to observation with future high-precision detectors.
{"title":"Gravitational quasinormal modes of Dymnikova black holes","authors":"Bekir Can Lütfüoğlu , Erdinç Ulaş Saka , Abubakir Shermatov , Javlon Rayimbaev , Inomjon Ibragimov , Sokhibjan Muminov","doi":"10.1016/j.aop.2026.170360","DOIUrl":"10.1016/j.aop.2026.170360","url":null,"abstract":"<div><div>We investigate gravitational quasinormal modes of the Dymnikova black hole, a regular spacetime in which the central singularity is replaced by a de Sitter core. This geometry, originally proposed as a phenomenological model, also arises naturally in the framework of Asymptotically Safe gravity, where quantum corrections lead to a scale-dependent modification of the Schwarzschild solution. Focusing on axial gravitational perturbations, we compute the dominant quasinormal frequencies using the WKB method with Padé approximants and verify the results with time-domain integration. We find that the introduction of the quantum parameter <span><math><msub><mrow><mi>l</mi></mrow><mrow><mi>cr</mi></mrow></msub></math></span> leads to systematic deviations from the Schwarzschild spectrum: the real oscillation frequency decreases as <span><math><msub><mrow><mi>l</mi></mrow><mrow><mi>cr</mi></mrow></msub></math></span> increases, while the damping rate also becomes smaller, implying longer-lived modes. In the limit of large <span><math><msub><mrow><mi>l</mi></mrow><mrow><mi>cr</mi></mrow></msub></math></span>, the quasinormal spectrum smoothly approaches the Schwarzschild case. These results suggest that even though the corrections are localized near the horizon, they leave imprints in the gravitational-wave ringdown which may become accessible to observation with future high-precision detectors.</div></div>","PeriodicalId":8249,"journal":{"name":"Annals of Physics","volume":"487 ","pages":"Article 170360"},"PeriodicalIF":3.0,"publicationDate":"2026-01-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146037352","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}
Pub Date : 2026-01-23DOI: 10.1016/j.aop.2026.170361
Maxim Dvornikov
We study neutrino oscillations in external fields using the approach based on the quantum field theory (QFT). Neutrinos are virtual particles in this formalism. Neutrino mass eigenstates are supposed to be Dirac fermions. We consider two cases of external fields: the neutrino electroweak interaction with background matter and the interaction with an external magnetic field owing to the presence of the transition magnetic moment. The formalism used involves the dressed propagators of mass eigenstates in external fields. In the matter case, finding of these propagators for Dirac neutrinos has certain difficulties compared to the Majorana particles considered previously. These difficulties are overcome by regularizing the effective potential of the neutrino interaction with matter. The QFT formalism application to the spin-flavor precession also encounters certain peculiarities in the Dirac case compared to the Majorana one. They are related to the observability of right polarized Dirac neutrinos. We derive the matrix elements and the probabilities for Dirac neutrinos interacting with both types of external fields. In case of the spin-flavor precession, we obtain the small QFT contribution to the probabilities in addition to the prediction of the quantum mechanical approach.
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Pub Date : 2026-01-22DOI: 10.1016/j.aop.2026.170357
R.S. Facundo, I.V. Vancea
In this paper, we construct a new non-null torus-knotted gravitational monochromatic wave solution of the linearized Einstein equations in vacuum in flat space–time, in the gravitoelectromagnetic (GEM) framework, by analogy with classical electrodynamics. We derive the relevant geometric objects: the line element, the Riemann tensor, the Ricci tensor, the Ricci scalar, and the geodesic equation for this background. Also, we investigate two properties inherent to this solution due to its GEM origin: the dual GEM potential and GEM helicity. For this solution, the global knotted topology is the result of the full Fourier synthesis of monochromatic components, each carrying local topological information in their amplitude coefficients parametrized by coprime integer pairs and .
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Pub Date : 2026-01-21DOI: 10.1016/j.aop.2026.170356
Mauro Ballicchia , Clemens Etl , Mihail Nedjalkov , David K. Ferry , Hans Kosina , Josef Weinbub
The electric interaction between two nearby evolving electrons triggers the correlation between their waves and governs the operation of logical devices called Coulomb entanglers. Of technological interest, in the presence of magnetic fields, are multi-spatial evolution scenarios beyond pure state descriptions. The two-electron density matrix becomes eight-dimensional even for two-dimensional spatial cases, and is thus computationally prohibitive. In this work, we present two new approximations of the two-electron Wigner equation that aim at computational feasibility: a BBGKY approach for reducing the number of variables and a field approximation of the Coulomb-Wigner operator. They exhibit different conceptual aspects that illustrate alternative viewpoints on entanglement: only the evolution provided by the latter model satisfies the orthodox definition of entanglement. Our analysis, based on the Fredholm integral representation of the models, allows us to develop an intuitive picture and physical insight into the process.
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