Annals of Physics最新文献

{"title":"Theoretical study of topological magnon transport in α-RuCl3: Effects of interactions on thermal Hall conductivity","authors":"Hamid Mosadeq ,&nbsp;Mohammad-Hossein Zare","doi":"10.1016/j.aop.2026.170393","DOIUrl":"10.1016/j.aop.2026.170393","url":null,"abstract":"<div><div>The layered honeycomb material <span><math><mi>α</mi></math></span>-RuCl<span><math><msub><mrow></mrow><mrow><mn>3</mn></mrow></msub></math></span> represents a significant candidate for the realization of a Kitaev quantum spin liquid (QSL) due to its pronounced spin–orbit coupling and bond-directional interactions. Experimental observations of a half-quantized thermal Hall effect under applied magnetic fields indicate the potential presence of fractionalized excitations, possibly of Majorana origin. However, the lack of definitive theoretical and experimental consensus necessitates further investigation into related magnetic phases. This study concentrates on the partially polarized ferromagnetic phase of <span><math><mi>α</mi></math></span>-RuCl<span><math><msub><mrow></mrow><mrow><mn>3</mn></mrow></msub></math></span>, which exhibits critical symmetry features analogous to those of the QSL state and may display comparable topological thermal transport signatures. Utilizing the framework of linear spin-wave theory, we calculate the thermal Hall conductivity (<span><math><msubsup><mrow><mi>κ</mi></mrow><mrow><mi>TH</mi></mrow><mrow><mi>x</mi><mi>y</mi></mrow></msubsup></math></span>) for five representative sets of exchange parameters derived from an extended minimal <span><math><mrow><mi>K</mi><mi>J</mi><mi>Γ</mi><msup><mrow><mi>Γ</mi></mrow><mrow><mo>′</mo></mrow></msup><mi>J</mi><mn>3</mn></mrow></math></span> model. This Hamiltonian incorporates the first-neighbor Heisenberg interaction <span><math><mrow><mo>(</mo><mi>J</mi><mo>)</mo></mrow></math></span>, the Kitaev interaction <span><math><mrow><mo>(</mo><mi>K</mi><mo>)</mo></mrow></math></span>, and third-nearest-neighbor Heisenberg interactions <span><math><mrow><mo>(</mo><msub><mrow><mi>J</mi></mrow><mrow><mn>3</mn></mrow></msub><mo>)</mo></mrow></math></span>, in addition to off-diagonal <span><math><mi>Γ</mi></math></span> and <span><math><msup><mrow><mi>Γ</mi></mrow><mrow><mo>′</mo></mrow></msup></math></span> terms. Our analysis reveals model-dependent behavior in both the magnitude and sign of <span><math><msubsup><mrow><mi>κ</mi></mrow><mrow><mi>TH</mi></mrow><mrow><mi>x</mi><mi>y</mi></mrow></msubsup></math></span>, with temperature-dependent sign reversals observed in certain instances. Moreover, we demonstrate that the inclusion of the second-nearest-neighbor Dzyaloshinskii–Moriya (DM) interaction significantly modifies the magnonic Berry curvature and, consequently, the thermal Hall response. These findings provide a theoretical framework for the interpretation of thermal Hall experiments in <span><math><mi>α</mi></math></span>-RuCl<span><math><msub><mrow></mrow><mrow><mn>3</mn></mrow></msub></math></span> and emphasize the sensitivity of topological magnon transport to the microscopic details of interactions in frustrated quantum magnets.</div></div>","PeriodicalId":8249,"journal":{"name":"Annals of Physics","volume":"488 ","pages":"Article 170393"},"PeriodicalIF":3.0,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146186146","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":"Dirac fermions on a surface with localized strain","authors":"Samuel B.B. Almeida,&nbsp;J.E.G. Silva,&nbsp;C.A.S. Almeida","doi":"10.1016/j.aop.2026.170385","DOIUrl":"10.1016/j.aop.2026.170385","url":null,"abstract":"<div><div>We study the influence of a localized Gaussian deformation on massless Dirac fermions confined to a two-dimensional curved surface. Both in-plane and out-of-plane displacements are considered within the framework of elasticity theory. These deformations couple to the Dirac spinors via the spin connection and the vielbeins, leading to a position-dependent Fermi velocity and an effective geometric potential. We show that spin connection modifies the density of states near the origin and how this modification is altered by changing mechanical parameters. Analytical and numerical solutions reveal the emergence of asymptotically free states, but with changes in amplitude near the origin due to the modification of curvature mediated by Lamé coefficients. Upon introducing an external magnetic field, the effective potential becomes confining at large distances, producing localized Landau levels that concentrate near the deformation, thus enabling the evaluation of how mechanical coefficients affect the localization of states. A geometric Aharonov–Bohm phase is identified through the spinor holonomy. These results contribute to the understanding of strain-induced electronic effects in Dirac materials, such as graphene.</div></div>","PeriodicalId":8249,"journal":{"name":"Annals of Physics","volume":"488 ","pages":"Article 170385"},"PeriodicalIF":3.0,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146186560","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":"Fubini–Study geometry, dynamics, and entanglement in KSEA-coupled two-spin system under magnetic field: Implications for quantum teleportation","authors":"Brahim Amghar ,&nbsp;Mouhcine Yachi ,&nbsp;M’bark Amghar ,&nbsp;Abdallah Slaoui","doi":"10.1016/j.aop.2026.170386","DOIUrl":"10.1016/j.aop.2026.170386","url":null,"abstract":"<div><div>We present a unified geometric and dynamical framework to investigate a two-spin system governed by the XXX Heisenberg model in the presence of an external magnetic field and an additional anisotropic KSEA exchange interaction. Using the Fubini–Study formalism, we derive the metric tensor of the corresponding quantum state space and compute the related Gaussian curvature. Our analysis reveals that the system evolves on a closed, anisotropic two-dimensional manifold embedded in <span><math><mrow><mi>ℂ</mi><msup><mrow><mi>P</mi></mrow><mrow><mn>3</mn></mrow></msup></mrow></math></span>, whose geometry is tuned by interaction strengths, with a topological redundancy emerging during the system’s dynamics. We also examine the geometric phase for arbitrary and cyclic evolutions, identifying the KSEA interaction as the primary factor shaping its behavior. We investigate quantum dynamics through evolution speed, Fubini–Study distance, and the brachistochrone problem, finding that stronger KSEA coupling or a more intense magnetic field reduces the optimal evolution time, thereby accelerating state transformations. Entanglement, quantified by the concurrence measure, is stabilized through KSEA coupling and enhanced by the magnetic field. From a geometric perspective, entanglement reshapes the curvature and geometric phase accumulation, while from a dynamical perspective it accelerates evolution and lengthens geodesic paths between the two-spin states. Finally, our analysis is applied to the concrete task of quantum teleportation, where we show that teleportation fidelity is closely related to the Gaussian curvature, geometric phase, speed, Fubini–Study distance, and brachistochrone time, and that fine-tuning the KSEA coupling significantly enhances teleportation performance.</div></div>","PeriodicalId":8249,"journal":{"name":"Annals of Physics","volume":"488 ","pages":"Article 170386"},"PeriodicalIF":3.0,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146186559","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":"Observational constraints and geometric diagnostics of Barboza–Alcaniz and logarithmic dark energy parametrizations","authors":"Archana Dixit ,&nbsp;Saurabh Verma ,&nbsp;Anirudh Pradhan ,&nbsp;M.S. Barak","doi":"10.1016/j.aop.2026.170390","DOIUrl":"10.1016/j.aop.2026.170390","url":null,"abstract":"<div><div>This study investigates and compares two prominent two-dimensional dark energy (DE) parameterizations: Barboza–Alcaniz (BA) and Logarithmic forms by comparing them with a comprehensive set of observational data comprising Type Ia Supernovae (SNe Ia) from the Pantheon compilation, Baryon Acoustic Oscillations (DESI BAO), and Cosmic Chronometers (CC). The primary objective was to explore the constraining power and cosmological implications of each parameterization in light of the current data. After formulating the theoretical framework and background equations governing cosmic expansion, we employ Markov Chain Monte Carlo (MCMC) techniques using the emcee Python package to constrain the free parameters of each model. The best-fit values for parameters <span><math><msub><mrow><mi>ω</mi></mrow><mrow><mn>0</mn></mrow></msub></math></span>, <span><math><msub><mrow><mi>ω</mi></mrow><mrow><mi>a</mi></mrow></msub></math></span>, and <span><math><msub><mrow><mi>H</mi></mrow><mrow><mn>0</mn></mrow></msub></math></span> were extracted for each model using individual and combined datasets. The results include confidence contours at the levels <span><math><mrow><mn>1</mn><mi>σ</mi></mrow></math></span> and <span><math><mrow><mn>2</mn><mi>σ</mi></mrow></math></span>. Our findings demonstrate that both parameterizations are consistent with observational data, with logarithmic parameterization showing slightly better constraints in terms of parameter evolution. Furthermore, we employed a statefinder diagnostic to analyze the geometric behavior of the models, providing an effective distinction between the two DE scenarios. This study contributes to a deeper understanding of DE evolution and its constraints in light of current cosmological data.</div></div>","PeriodicalId":8249,"journal":{"name":"Annals of Physics","volume":"488 ","pages":"Article 170390"},"PeriodicalIF":3.0,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146186558","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":"Revealing gauge constraints in LQG-inspired Yang–Mills theory","authors":"Leonardo P.G. De Assis","doi":"10.1016/j.aop.2026.170381","DOIUrl":"10.1016/j.aop.2026.170381","url":null,"abstract":"<div><div>The consistent embedding of Loop Quantum Gravity (LQG) effects within the Standard Model requires a rigorous understanding of how Planck-scale deformations manifest at low energies. While phenomenological approaches often introduce canonical deformations with multiple free parameters to capture these effects, the physical requirement of gauge symmetry in the framework of a covariant Effective Field Theory (EFT) imposes strict conditions on the allowed interaction structure. In this paper, we demonstrate that these conditions act as physical selection rules for admissible quantum gravity models. By applying non-Abelian Ward identities and a covariant operator mapping to the dimension-six operator basis, we derive a fundamental on-shell equivalence between kinetic and cubic interaction terms. As a paradigmatic application, we show that the Levy–Helayël-Neto (LHN) framework – a candidate effective description of LQG – satisfies this physical requirement only when its parameters obey the specific algebraic relation: <span><span><span><math><mrow><mfrac><mrow><msub><mrow><mi>θ</mi></mrow><mrow><mn>3</mn></mrow></msub></mrow><mrow><msub><mrow><mi>θ</mi></mrow><mrow><mn>8</mn></mrow></msub></mrow></mfrac><mo>=</mo><mo>−</mo><mfrac><mrow><mn>1</mn></mrow><mrow><mn>2</mn></mrow></mfrac><mspace></mspace><mfenced><mrow><mn>1</mn><mo>+</mo><msub><mrow><mi>θ</mi></mrow><mrow><mn>7</mn></mrow></msub><msup><mrow><mrow><mo>(</mo><mrow><mfrac><mrow><msub><mrow><mi>ℓ</mi></mrow><mrow><mi>P</mi></mrow></msub></mrow><mrow><mi>L</mi></mrow></mfrac></mrow><mo>)</mo></mrow></mrow><mrow><mn>2</mn><mo>+</mo><mn>2</mn><mi>Υ</mi></mrow></msup></mrow></mfenced><mo>+</mo><mi>O</mi><mrow><mo>(</mo><msub><mrow><mi>ℓ</mi></mrow><mrow><mi>P</mi></mrow></msub><mo>)</mo></mrow><mo>.</mo></mrow></math></span></span></span>It must be highlighted that this result advances the physical understanding of LQG phenomenology by revealing that the apparent freedom in defining the Hamiltonian is illusory; the parameters are bound by the necessity of preserving the gauge structure of the Standard Model.</div></div>","PeriodicalId":8249,"journal":{"name":"Annals of Physics","volume":"488 ","pages":"Article 170381"},"PeriodicalIF":3.0,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146186556","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":"Thermal fluctuation and tidal force of scalar tensor–vector gravity charged black hole","authors":"Jiafeng Guo ,&nbsp;A. Eid ,&nbsp;Faisal Javed ,&nbsp;M. Zeeshan Gul ,&nbsp;Javlon Rayimbaev ,&nbsp;Munisbek Akhmedov ,&nbsp;N. Mustapha ,&nbsp;Yunus Turaev","doi":"10.1016/j.aop.2026.170369","DOIUrl":"10.1016/j.aop.2026.170369","url":null,"abstract":"<div><div>This analysis focuses on the understanding of the thermodynamic, quantum, and dynamical properties of charged black holes (BHs) in the context of scalar–tensor–vector gravity (STVG). Considering the effect of the MOG parameter (<span><math><mi>χ</mi></math></span>) and the electric charge <span><math><mrow><mo>(</mo><mi>Q</mi><mo>)</mo></mrow></math></span>, we discuss how modified gravity affects the stability of BHs, the phase transitions, and the geometry of the spacetime around the BHs. Thermodynamic analysis through the heat capacity, entropy, and free energy shows the presence of multiple stability phases, where larger <span><math><mi>χ</mi></math></span> values lead to an enhancement of quantum fluctuations and a larger alteration of the equilibration, and where <span><math><mi>Q</mi></math></span> values lead to a thermodynamic stabilization. The thermodynamic analysis also shows the effect of higher-order entropy correction terms resulting important quantum effects surrounding the event horizon. The analysis of Hawking emission shows the radiation gets weaker with larger Q values and gets stronger with larger <span><math><mi>χ</mi></math></span> values. This highlights a competition between electromagnetic suppression and gravitational amplification. Also, perturbation theory analysis shows scalar and electromagnetic perturbation with <span><math><mi>χ</mi></math></span> and Q diminishing transmission probabilities by enlarging the effective potential barrier. Geodesic deviation and tidal analysis shows weaker coupling and radial symmetrical perturbation. In summary, the findings indicate that STVG demonstrates a greater range of thermodynamic behavior and more pronounced curvature effects relative to General Relativity (GR). This provides a deeper understanding of the thermodynamics of BHs, not only from STVG perspectives but also from other frameworks of modified gravity.</div></div>","PeriodicalId":8249,"journal":{"name":"Annals of Physics","volume":"488 ","pages":"Article 170369"},"PeriodicalIF":3.0,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146186563","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":"Non-commutative fluid as an alternative driver of cosmic acceleration: Confronting DESI observations","authors":"Raj Kumar Das ,&nbsp;Arpan Krishna Mitra","doi":"10.1016/j.aop.2026.170384","DOIUrl":"10.1016/j.aop.2026.170384","url":null,"abstract":"<div><div>We present a novel formulation for the Hubble parameter derived from Newtonian cosmology, incorporating non-commutative fluid dynamics through a deformed Poisson bracket structure. This approach introduces a new cosmological parameter, denoted by <span><math><mi>σ</mi></math></span>, which emerges naturally from the underlying non-commutative framework. It gives rise to a source term in the background fluid continuity equation, thereby leading to an apparent type of matter creation picture through the resulting non-conservation. Remarkably, the resulting Hubble function accounts for the observed accelerated expansion of the universe without invoking any external dark energy component or cosmological constant. Instead, the parameter <span><math><mi>σ</mi></math></span> effectively serves as the driver of acceleration. We further examine the observational constraints on <span><math><mi>σ</mi></math></span> using current cosmological data, including the recent Dark Energy Spectroscopic Instrument(DESI) dataset, demonstrating its viability as an alternative explanation for late-time cosmic acceleration within a non-commutative cosmological model.</div></div>","PeriodicalId":8249,"journal":{"name":"Annals of Physics","volume":"488 ","pages":"Article 170384"},"PeriodicalIF":3.0,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146186148","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":"Bridging quantum and classical descriptions of spin dynamics in a Dzyaloshinsky–Moriya trimer","authors":"Robert Wieser ,&nbsp;Raúl Sánchez Galán","doi":"10.1016/j.aop.2026.170389","DOIUrl":"10.1016/j.aop.2026.170389","url":null,"abstract":"<div><div>The spin dynamics of a trimer with Dzyaloshinsky–Moriya (DM) interaction are investigated within a unified Hamiltonian framework that connects quantum-mechanical and semiclassical descriptions. The interpolation between the two regimes is realized by solving the modified Gisin–Schrödinger equation, in which the relative weight of quantum coherence and local mean-field contributions is continuously tuned. The resulting dynamical behavior is analyzed and summarized in a ground state diagram that illustrates how the character of the spin motion evolves from fully quantum to semiclassical as the DM interaction is treated at different levels of approximation. In the last part of the publication, the chiral spin dynamics originally proposed by Da-Wei Wang et al. is examined theoretically, taking into account its behavior at the boundary between quantum and classical physics.</div></div>","PeriodicalId":8249,"journal":{"name":"Annals of Physics","volume":"488 ","pages":"Article 170389"},"PeriodicalIF":3.0,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146186149","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":"Non-exotic wormholes in f(R,Lm) gravity","authors":"S. Rastgoo,&nbsp;F. Parsaei","doi":"10.1016/j.aop.2026.170394","DOIUrl":"10.1016/j.aop.2026.170394","url":null,"abstract":"<div><div>In the present analysis, we examine the potential existence of generalized wormhole models within the framework of newly developed extended <span><math><mrow><mi>f</mi><mrow><mo>(</mo><mi>R</mi><mo>,</mo><msub><mrow><mi>L</mi></mrow><mrow><mi>m</mi></mrow></msub><mo>)</mo></mrow></mrow></math></span> gravity. We investigate both a linear model, <span><math><mrow><mi>f</mi><mrow><mo>(</mo><mi>R</mi><mo>,</mo><msub><mrow><mi>L</mi></mrow><mrow><mi>m</mi></mrow></msub><mo>)</mo></mrow><mo>=</mo><mi>α</mi><mfrac><mrow><mi>R</mi></mrow><mrow><mn>2</mn></mrow></mfrac><mo>+</mo><mi>β</mi><msub><mrow><mi>L</mi></mrow><mrow><mi>m</mi></mrow></msub></mrow></math></span>, and a non-linear model, <span><math><mrow><mi>f</mi><mrow><mo>(</mo><mi>R</mi><mo>,</mo><msub><mrow><mi>L</mi></mrow><mrow><mi>m</mi></mrow></msub><mo>)</mo></mrow><mo>=</mo><mfrac><mrow><mi>R</mi></mrow><mrow><mn>2</mn></mrow></mfrac><mo>+</mo><msubsup><mrow><mi>L</mi></mrow><mrow><mi>m</mi></mrow><mrow><mi>α</mi></mrow></msubsup></mrow></math></span>, to analyze traversable wormholes. By employing the variational approach, we derive modified versions of the field equations under the influence of an anisotropic matter source. A power-law shape function is applied, resulting in a linear equation of state for both radial and lateral pressures. Furthermore, we explore solutions characterized by a variable equation of state parameter. It was observed that the violation of energy conditions is influenced by the parameters <span><math><mi>α</mi></math></span> and <span><math><mi>β</mi></math></span>. A wide range of non-exotic wormhole solutions was discovered, dependent on the specific parameters of the model. We demonstrate that wormholes with power-law shape functions yield solutions that comply with the energy conditions in both linear and non-linear forms of <span><math><mrow><mi>f</mi><mrow><mo>(</mo><mi>R</mi><mo>,</mo><msub><mrow><mi>L</mi></mrow><mrow><mi>m</mi></mrow></msub><mo>)</mo></mrow></mrow></math></span>. It is shown that the non-exotic wormhole solutions obtained within this framework are not isotropic.</div></div>","PeriodicalId":8249,"journal":{"name":"Annals of Physics","volume":"488 ","pages":"Article 170394"},"PeriodicalIF":3.0,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146186150","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":"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":"&lt;div&gt;&lt;div&gt;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 &lt;span&gt;&lt;math&gt;&lt;msup&gt;&lt;mrow&gt;&lt;mi&gt;S&lt;/mi&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mi&gt;D&lt;/mi&gt;&lt;/mrow&gt;&lt;/msup&gt;&lt;/math&gt;&lt;/span&gt;, we trace the one-loop phase &lt;span&gt;&lt;math&gt;&lt;msup&gt;&lt;mrow&gt;&lt;mi&gt;i&lt;/mi&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mi&gt;D&lt;/mi&gt;&lt;mo&gt;+&lt;/mo&gt;&lt;mn&gt;2&lt;/mn&gt;&lt;/mrow&gt;&lt;/msup&gt;&lt;/math&gt;&lt;/span&gt; to a finite set of scalar and conformal Killing modes and show that, once the worldline is included, the &lt;span&gt;&lt;math&gt;&lt;mrow&gt;&lt;mo&gt;(&lt;/mo&gt;&lt;mi&gt;D&lt;/mi&gt;&lt;mo&gt;−&lt;/mo&gt;&lt;mn&gt;1&lt;/mn&gt;&lt;mo&gt;)&lt;/mo&gt;&lt;/mrow&gt;&lt;/math&gt;&lt;/span&gt; transverse negative modes cancel the corresponding &lt;span&gt;&lt;math&gt;&lt;mrow&gt;&lt;mo&gt;(&lt;/mo&gt;&lt;mi&gt;D&lt;/mi&gt;&lt;mo&gt;−&lt;/mo&gt;&lt;mn&gt;1&lt;/mn&gt;&lt;mo&gt;)&lt;/mo&gt;&lt;/mrow&gt;&lt;/math&gt;&lt;/span&gt; conformal Killing directions mode by mode. The residual fixed-&lt;span&gt;&lt;math&gt;&lt;mi&gt;β&lt;/mi&gt;&lt;/math&gt;&lt;/span&gt; phase from the global conformal factor and reparametrizations is removed by imposing the Hamiltonian constraint &lt;span&gt;&lt;math&gt;&lt;mrow&gt;&lt;msub&gt;&lt;mrow&gt;&lt;mi&gt;H&lt;/mi&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mtext&gt;patch&lt;/mtext&gt;&lt;/mrow&gt;&lt;/msub&gt;&lt;mo&gt;−&lt;/mo&gt;&lt;msub&gt;&lt;mrow&gt;&lt;mi&gt;H&lt;/mi&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mtext&gt;clock&lt;/mtext&gt;&lt;/mrow&gt;&lt;/msub&gt;&lt;mo&gt;−&lt;/mo&gt;&lt;mi&gt;ν&lt;/mi&gt;&lt;mo&gt;=&lt;/mo&gt;&lt;mn&gt;0&lt;/mn&gt;&lt;/mrow&gt;&lt;/math&gt;&lt;/span&gt; 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 &lt;span&gt;&lt;math&gt;&lt;msup&gt;&lt;mrow&gt;&lt;mi&gt;S&lt;/mi&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mi&gt;D&lt;/mi&gt;&lt;/mrow&gt;&lt;/msup&gt;&lt;/math&gt;&lt;/span&gt; saddle in the probe regime &lt;span&gt;&lt;math&gt;&lt;mrow&gt;&lt;mi&gt;G&lt;/mi&gt;&lt;msub&gt;&lt;mrow&gt;&lt;mi&gt;E&lt;/mi&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mi&gt;clock&lt;/mi&gt;&lt;/mrow&gt;&lt;/msub&gt;&lt;mo&gt;/&lt;/mo&gt;&lt;mi&gt;R&lt;/mi&gt;&lt;mo&gt;≪&lt;/mo&gt;&lt;mn&gt;1&lt;/mn&gt;&lt;/mrow&gt;&lt;/math&gt;&lt;/span&gt;; 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 &lt;span&gt;&lt;math&gt;&lt;mrow&gt;&lt;mi&gt;T&lt;/mi&gt;&lt;mo&gt;→&lt;/mo&gt;&lt;mn&gt;0&lt;/mn&gt;&lt;/mrow&gt;&lt;/math&gt;&lt;/span&gt; can account for the observed value of the cosmological constant and for the origin of the fundamental constants &lt;span&gt;&lt;math&gt;&lt;mrow&gt;&lt;mo&gt;(&lt;/mo&gt;&lt;mo&gt;ħ&lt;/mo&gt;&lt;mo&gt;,&lt;/mo&gt;&lt;mi&gt;G&lt;/mi&gt;&lt;mo&gt;,&lt;/mo&gt;&lt;mi&gt;c&lt;/mi&gt;&lt;mo&gt;)&lt;/mo&gt;&lt;/mrow&gt;&lt;/math&gt;&lt;/span&gt; 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 &lt;span&gt;&lt;math&gt;&lt;mrow&gt;&lt;mi&gt;U&lt;/mi&gt;&lt;msup&gt;&lt;mrow&gt;&lt;mrow&gt;&lt;mo&gt;(&lt;/mo&gt;&lt;mn&gt;1&lt;/mn&gt;&lt;mo&gt;)&lt;/mo&gt;&lt;/mrow&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mn&gt;2&lt;/mn&gt;&lt;/mrow&gt;&lt;/msup&gt;&lt;/mrow&gt;&lt;/math&gt;&lt;/span&gt; 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.&lt;/div&gt;&lt;div&gt;&lt;strong&gt;Summary of con","PeriodicalId":8249,"journal":{"name":"Annals of Physics","volume":"487 ","pages":"Article 170364"},"PeriodicalIF":3.0,"publicationDate":"2026-04-01","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}