Fortschritte Der Physik-Progress of Physics最新文献

{"title":"Algebraic Realisation of the Zamolodchikov Metric in Narain Theories","authors":"E. H Saidi, R. Sammani","doi":"10.1002/prop.70098","DOIUrl":"https://doi.org/10.1002/prop.70098","url":null,"abstract":"<div>\u0000 \u0000 <p>We revisit Narain conformal field theories (<span></span><math>\u0000 <semantics>\u0000 <msub>\u0000 <mi>NCFT</mi>\u0000 <mn>2</mn>\u0000 </msub>\u0000 <annotation>${rm NCFT}_{2}$</annotation>\u0000 </semantics></math>)from an algebraic perspective based on finite dimensional Lie algebras <span></span><math>\u0000 <semantics>\u0000 <mi>g</mi>\u0000 <annotation>$mathbf {g}$</annotation>\u0000 </semantics></math> and representations <span></span><math>\u0000 <semantics>\u0000 <msub>\u0000 <mi>R</mi>\u0000 <mi>g</mi>\u0000 </msub>\u0000 <annotation>$mathcal {R}_{mathbf {g}}$</annotation>\u0000 </semantics></math>, and show how the root and weight lattices can encode the momenta and subsequently the partition functions of Narain theories. In this framework, we construct a realisation of the Zamolodchikov metric of the moduli space <span></span><math>\u0000 <semantics>\u0000 <msub>\u0000 <mi>M</mi>\u0000 <mi>g</mi>\u0000 </msub>\u0000 <annotation>$mathcal {M}_{mathbf {g}}$</annotation>\u0000 </semantics></math> in terms of Lie algebraic data, namely, the Cartan matrix <span></span><math>\u0000 <semantics>\u0000 <msub>\u0000 <mi>K</mi>\u0000 <mi>g</mi>\u0000 </msub>\u0000 <annotation>${rm K}_{mathbf {g}}$</annotation>\u0000 </semantics></math> and its inverse <span></span><math>\u0000 <semantics>\u0000 <msubsup>\u0000 <mi>K</mi>\u0000 <mi>g</mi>\u0000 <mrow>\u0000 <mo>−</mo>\u0000 <mn>1</mn>\u0000 </mrow>\u0000 </msubsup>\u0000 <annotation>${rm K}_{ mathbf {g}}^{-1}$</annotation>\u0000 </semantics></math>. Properties regarding the ensemble averaging of these CFTs and their holographic dual are also derived. Additionally, we discuss possible generalisations to NCFTs having dis-symmetric central charges <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <mrow>\u0000 <mo>(</mo>\u0000 <msub>\u0000 <mi>c</mi>\u0000 <mi>L</mi>\u0000 </msub>\u0000 <mo>,</mo>\u0000 <msub>\u0000 <mi>c</mi>\u0000 <mi>R</mi>\u0000 </msub>\u0000 <mo>)</mo>\u0000 </mrow>\u0000 <mo>=</mo>\u0000 <mrow>\u0000 <mo>(</mo>\u0000 <mi>s</mi>\u0000 <mo>,</mo>\u0000 <mi>r</mi>\u0000 <mo>)</mo>\u0000 </mrow>\u0000 </mrow>\u0000 <annotation>$(mathrm{c}_{L},mathrm{c}_{R})=(mathrm{s}, mathrm{r})$</annotation>\u0000 </semantics","PeriodicalId":55150,"journal":{"name":"Fortschritte Der Physik-Progress of Physics","volume":"74 4","pages":""},"PeriodicalIF":7.8,"publicationDate":"2026-04-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147683810","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":"Tessellation Groups, Harmonic Analysis on Non-Compact Symmetric Spaces and the Heat Kernel in View of Cartan Convolutional Neural networks","authors":"Pietro Fré, Federico Milanesio, Marcelo Oyarzo, Matteo Santoro, Mario Trigiante","doi":"10.1002/prop.70099","DOIUrl":"https://doi.org/10.1002/prop.70099","url":null,"abstract":"<p>In this paper, we continue the development of the Cartan neural networks programme, launched with three previous publications, by focusing on some mathematical foundational aspects that we deem necessary for our next steps forward. The mathematical and conceptual results are diverse and span various mathematical fields, but the inspiring motivation is unified. The aim is to introduce layers that are mathematically modeled as non-compact symmetric spaces, each mapped onto the next one by solvable group homomorphisms. In particular, in the spirit of convolutional neural networks, we have introduced the notion of Tits–Satake (TS) vector bundles where the TS submanifold is the base space. Within this framework, the tiling of the base manifold, the representation of bundle sections using harmonics, and the need for a general theory of separator walls motivated a series of mathematical investigations that produced both definite and partial results. Specifically, we present the group theoretical construction of the separators for all non-compact symmetric spaces <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <mi>U</mi>\u0000 <mo>/</mo>\u0000 <mi>H</mi>\u0000 </mrow>\u0000 <annotation>$mathrm{U/H}$</annotation>\u0000 </semantics></math>, as well as of the <span></span><math>\u0000 <semantics>\u0000 <msub>\u0000 <mi>Δ</mi>\u0000 <mrow>\u0000 <mn>8</mn>\u0000 <mo>,</mo>\u0000 <mn>3</mn>\u0000 <mo>,</mo>\u0000 <mn>2</mn>\u0000 </mrow>\u0000 </msub>\u0000 <annotation>$Delta _{8,3,2}$</annotation>\u0000 </semantics></math> tiling group and its normal Fuchsian subgroups, respectively, yielding the uniformization of the genus <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <mi>g</mi>\u0000 <mo>=</mo>\u0000 <mn>3</mn>\u0000 </mrow>\u0000 <annotation>$g=3$</annotation>\u0000 </semantics></math> Fermat quartic and of the genus <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <mi>g</mi>\u0000 <mo>=</mo>\u0000 <mn>2</mn>\u0000 </mrow>\u0000 <annotation>$g=2$</annotation>\u0000 </semantics></math> Bolza surface. The quotient automorphic groups are studied. Furthermore, we found a new representation of the Laplacian Green function and the Heat Kernel on Hyperbolic Spaces <span></span><math>\u0000 <semantics>\u0000 <msup>\u0000 <mi>H</mi>\u0000 <mi>n</mi>\u0000 </msup>\u0000 <annotation>$mathbb {H}^{n}$</annotation>\u0000 </semantics></math>, and a setup for the construction of th","PeriodicalId":55150,"journal":{"name":"Fortschritte Der Physik-Progress of Physics","volume":"74 4","pages":""},"PeriodicalIF":7.8,"publicationDate":"2026-04-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/prop.70099","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147683606","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":"Kaniadakis Holographic Dark Energy Behavior in f(Q) Theory","authors":"Sinem Kalkan,&nbsp;Can Aktaş","doi":"10.1002/prop.70102","DOIUrl":"https://doi.org/10.1002/prop.70102","url":null,"abstract":"<p>In this study, the cosmological behavior of the Kaniadakis holographic dark energy model is investigated under the <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <mi>f</mi>\u0000 <mo>(</mo>\u0000 <mi>Q</mi>\u0000 <mo>)</mo>\u0000 </mrow>\u0000 <annotation>$f(Q)$</annotation>\u0000 </semantics></math> theory within the framework of a flat Friedmann–Robertson–Walker (FRW) universe. The generalized holographic energy density based on Kaniadakis entropy is modeled using the Hubble horizon infrared cutoff scale, and the field equations are solved analytically. Using the obtained solutions, the evolution of fundamental cosmological quantities such as the deceleration parameter, the equation of state parameter, and the statefinder parameters as a function of time and redshift is analyzed in detail. It is shown that the model successfully describes the transition to time-accelerated expansion and gives a value of <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <msub>\u0000 <mi>q</mi>\u0000 <mn>0</mn>\u0000 </msub>\u0000 <mo>≈</mo>\u0000 <mo>−</mo>\u0000 <mn>0.508</mn>\u0000 </mrow>\u0000 <annotation>$q_0 approx -0.508$</annotation>\u0000 </semantics></math>, consistent with current observational data. Furthermore, it is observed that in the statefinder plane, the model exhibits a dynamic dark energy behavior close to the <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <mi>Λ</mi>\u0000 <mi>CDM</mi>\u0000 </mrow>\u0000 <annotation>$Lambda{rm CDM}$</annotation>\u0000 </semantics></math> scenario, but tends toward the de Sitter universe in the long term. The results show that the <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <mi>f</mi>\u0000 <mo>(</mo>\u0000 <mi>Q</mi>\u0000 <mo>)</mo>\u0000 </mrow>\u0000 <annotation>$f(Q)$</annotation>\u0000 </semantics></math> theory of gravity, when considered together with Kaniadakis holographic dark energy, offers a consistent and viable framework for explaining the late-stage accelerating expansion of the universe.</p>","PeriodicalId":55150,"journal":{"name":"Fortschritte Der Physik-Progress of Physics","volume":"74 4","pages":""},"PeriodicalIF":7.8,"publicationDate":"2026-04-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/prop.70102","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147683685","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":"Noncoincidence f(Q)-Cosmology with Dark Matter Coupled to Gravity","authors":"A. Abebe,&nbsp;P. S. Apostolopoulos,&nbsp;A. Giacomini,&nbsp;G. Leon,&nbsp;F. Moncada,&nbsp;A. Paliathanasis","doi":"10.1002/prop.70100","DOIUrl":"https://doi.org/10.1002/prop.70100","url":null,"abstract":"<div>\u0000 \u0000 <p>We investigate Friedmann–Lemaître–Robertson–Walker (FLRW) cosmology in the framework of symmetric teleparallel <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <mi>f</mi>\u0000 <mo>(</mo>\u0000 <mi>Q</mi>\u0000 <mo>)</mo>\u0000 </mrow>\u0000 <annotation>$f(Q)$</annotation>\u0000 </semantics></math> gravity with a nonminimal coupling between dark matter and the gravitational field. In the noncoincidence gauge, the field equations admit an equivalent multi-scalar field representation, which we investigate the phase-space using the Hubble-normalization approach. We classify all stationary points for arbitrary function <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <mi>f</mi>\u0000 <mo>(</mo>\u0000 <mi>Q</mi>\u0000 <mo>)</mo>\u0000 </mrow>\u0000 <annotation>$f(Q)$</annotation>\u0000 </semantics></math> and we discuss the physical properties of the asymptotic solutions. For the power-law theory, we perform a detailed stability analysis and show that the de Sitter solution is the unique future attractor, while the matter-dominated point appears as a saddle point. Moreover, there exist a family of scaling solutions that can be related to inflationary dynamics. In contrast with uncoupled <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <mi>f</mi>\u0000 <mo>(</mo>\u0000 <mi>Q</mi>\u0000 <mo>)</mo>\u0000 </mrow>\u0000 <annotation>$f(Q)$</annotation>\u0000 </semantics></math> models, the presence of the coupling introduces a viable matter-dominated era alongside late-time accelerated expansion. Our study shows that the coupling function plays a crucial role in cosmological dynamics in <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <mi>f</mi>\u0000 <mo>(</mo>\u0000 <mi>Q</mi>\u0000 <mo>)</mo>\u0000 </mrow>\u0000 <annotation>$f(Q)$</annotation>\u0000 </semantics></math> gravity.</p>\u0000 </div>","PeriodicalId":55150,"journal":{"name":"Fortschritte Der Physik-Progress of Physics","volume":"74 4","pages":""},"PeriodicalIF":7.8,"publicationDate":"2026-04-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147683657","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":"Impact of Quantum Gravity on the UV Sensitivity of Extremal Black Holes","authors":"Francesco Del Porro,&nbsp;Francesco Ferrarin,&nbsp;Alessia Platania","doi":"10.1002/prop.70101","DOIUrl":"https://doi.org/10.1002/prop.70101","url":null,"abstract":"<p>Recent work has revealed that extremal Kerr black holes may exhibit a sensitivity to higher-derivative corrections to Einstein's equations, displaying singularities in the tidal forces at the horizon. However, in a purely gravitational context, this “ultraviolet sensitivity” translates into a strong dependence on the Wilson coefficients in the low-energy effective field theory. These, in turn, are fixed by the underlying theory of quantum gravity in the ultraviolet. We find a prediction for these coefficients within the framework of asymptotically safe quantum gravity, and show that, if the quantum gravity scale is trans-Planckian, this horizon-scale ultraviolet sensitivity is avoided.</p>","PeriodicalId":55150,"journal":{"name":"Fortschritte Der Physik-Progress of Physics","volume":"74 4","pages":""},"PeriodicalIF":7.8,"publicationDate":"2026-04-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/prop.70101","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147683351","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":"Localized Five-Dimensional Rotating Brane-World Black Hole Analytically Connected to an to an AdS5 Boundary","authors":"Milko Estrada,&nbsp;Francisco Tello-Ortiz","doi":"10.1002/prop.70096","DOIUrl":"https://doi.org/10.1002/prop.70096","url":null,"abstract":"<div>\u0000 \u0000 <p>We provide a method to describe the geometry of an analytic, exponentially localized <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <mn>5</mn>\u0000 <mi>D</mi>\u0000 </mrow>\u0000 <annotation>$5D$</annotation>\u0000 </semantics></math> rotating braneworld black hole using the <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <mn>5</mn>\u0000 <mi>D</mi>\u0000 </mrow>\u0000 <annotation>$5D$</annotation>\u0000 </semantics></math> Janis–Newman algorithm in Hopf coordinates. The induced metric on the brane matches the standard <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <mn>4</mn>\u0000 <mi>D</mi>\u0000 </mrow>\u0000 <annotation>$4D$</annotation>\u0000 </semantics></math> Kerr spacetime. Two curvature singularities arise: one confined to the 3-brane at <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <mi>z</mi>\u0000 <mo>=</mo>\u0000 <mi>r</mi>\u0000 <mo>=</mo>\u0000 <mn>0</mn>\u0000 </mrow>\u0000 <annotation>$z = r = 0$</annotation>\u0000 </semantics></math>, and another that, on the brane, reproduces the Kerr singularity at <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <mi>r</mi>\u0000 <mo>=</mo>\u0000 <mn>0</mn>\u0000 </mrow>\u0000 <annotation>$r = 0$</annotation>\u0000 </semantics></math>, <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <mover>\u0000 <mi>θ</mi>\u0000 <mo>¯</mo>\u0000 </mover>\u0000 <mo>=</mo>\u0000 <mi>π</mi>\u0000 <mo>/</mo>\u0000 <mn>2</mn>\u0000 </mrow>\u0000 <annotation>$bar{theta } = pi /2$</annotation>\u0000 </semantics></math>. The inner and event horizons, together with the stationary limit hypersurfaces, extend into the extra dimension in a pancake-like shape. We describe their behavior in the bulk. The energy–momentum tensor represents a source transitioning from an anisotropic, nondiagonal structure to a vacuum with a negative cosmological constant. Thus, the localized black hole connects to an AdS₅ boundary. The geometry is supported by a nondiagonal anisotropic fluid in the bulk, requiring no matter on the brane. To evaluate the energy conditions, we use a one-form from the dual basis that yields a diagonal energy–momentum tensor. The energy conditions are satisfied close to the brane, while they are violated at a location outside the brane but within the extension of the event horizon. The latter is required to support the rotating geometry.</p></div>","PeriodicalId":55150,"journal":{"name":"Fortschritte Der Physik-Progress of Physics","volume":"74 4","pages":""},"PeriodicalIF":7.8,"publicationDate":"2026-04-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147682997","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":"RaCS: Near-Zero-Error Classical Data Encoding on Photonic Quantum Processors via Redundancy-Assisted Coherent-State Codes","authors":"Dennis Delali Kwesi Wayo,&nbsp;Sven Groppe","doi":"10.1002/prop.70095","DOIUrl":"https://doi.org/10.1002/prop.70095","url":null,"abstract":"&lt;div&gt;\u0000 \u0000 &lt;p&gt;This work presents a systematic evaluation of near-zero-error encoding strategies for coherent-state quantum communication, comparing homodyne and threshold detection across alphabet sizes &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 &lt;mi&gt;M&lt;/mi&gt;\u0000 &lt;mo&gt;∈&lt;/mo&gt;\u0000 &lt;mo&gt;{&lt;/mo&gt;\u0000 &lt;mn&gt;3&lt;/mn&gt;\u0000 &lt;mo&gt;,&lt;/mo&gt;\u0000 &lt;mn&gt;5&lt;/mn&gt;\u0000 &lt;mo&gt;,&lt;/mo&gt;\u0000 &lt;mn&gt;7&lt;/mn&gt;\u0000 &lt;mo&gt;}&lt;/mo&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;annotation&gt;$M in lbrace 3,5,7rbrace$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt;. Simulations were performed for coherent amplitudes &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 &lt;mi&gt;α&lt;/mi&gt;\u0000 &lt;mo&gt;∈&lt;/mo&gt;\u0000 &lt;mo&gt;{&lt;/mo&gt;\u0000 &lt;mn&gt;0.20&lt;/mn&gt;\u0000 &lt;mo&gt;,&lt;/mo&gt;\u0000 &lt;mn&gt;0.40&lt;/mn&gt;\u0000 &lt;mo&gt;,&lt;/mo&gt;\u0000 &lt;mn&gt;0.80&lt;/mn&gt;\u0000 &lt;mo&gt;}&lt;/mo&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;annotation&gt;$alpha in lbrace 0.20,0.40,0.80rbrace$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt; and channel transmittance values &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 &lt;mi&gt;η&lt;/mi&gt;\u0000 &lt;mo&gt;∈&lt;/mo&gt;\u0000 &lt;mo&gt;[&lt;/mo&gt;\u0000 &lt;mn&gt;0.5&lt;/mn&gt;\u0000 &lt;mo&gt;,&lt;/mo&gt;\u0000 &lt;mn&gt;1.0&lt;/mn&gt;\u0000 &lt;mo&gt;]&lt;/mo&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;annotation&gt;$eta in [0.5,1.0]$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt;, enabling a detailed characterization of bit-error rate (BER), optimal operating points, and information-theoretic performance. Threshold detection was found to tend to saturate near &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 &lt;mi&gt;BER&lt;/mi&gt;\u0000 &lt;mo&gt;≈&lt;/mo&gt;\u0000 &lt;mn&gt;0.5&lt;/mn&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;annotation&gt;$mathrm{BER}approx 0.5$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt; for all &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mi&gt;M&lt;/mi&gt;\u0000 &lt;annotation&gt;$M$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt;, consistent with its limited ability to discriminate low-energy coherent states. In contrast, homodyne detection exhibited exponential-like BER suppression, reaching values below &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;msup&gt;\u0000 &lt;mn&gt;10&lt;/mn&gt;\u0000 &lt;mrow&gt;\u0000 &lt;mo&gt;−&lt;/mo&gt;\u0000 &lt;mn&gt;2&lt;/mn&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;/msup&gt;\u0000 &lt;annotation&gt;$10^{-2}$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt; for &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 &lt;mi&gt;α&lt;/mi&gt;\u0000 &lt;mo&gt;=&lt;/mo&gt;\u0000 &lt;mn&gt;0.80&lt;/mn&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;annotation&gt;$alpha =0.80$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt;, at &lt;span&gt;&lt;/span","PeriodicalId":55150,"journal":{"name":"Fortschritte Der Physik-Progress of Physics","volume":"74 4","pages":""},"PeriodicalIF":7.8,"publicationDate":"2026-03-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147683011","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":"A Dynamical Systems Perspective on the Thermodynamics of Late-Time Cosmology","authors":"Dipayan Mukherjee,&nbsp;Harkirat Singh Sahota,&nbsp;Swati Gavas","doi":"10.1002/prop.70094","DOIUrl":"https://doi.org/10.1002/prop.70094","url":null,"abstract":"<div>\u0000 \u0000 <p>A thermodynamic description of cosmological spacetimes may provide insights into the fundamentals of the cosmic evolution that remain otherwise obscure, similar to “black hole thermodynamics.” We investigate the thermodynamic properties of late-time cosmological evolution using the dynamical systems approach, focusing on <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <mi>Λ</mi>\u0000 <mi>CDM</mi>\u0000 </mrow>\u0000 <annotation>$Lambda{rm CDM}$</annotation>\u0000 </semantics></math> model and scalar field models with exponential potentials. Thermodynamic quantities obtained through the Hayward–Kodama formalism are mapped onto the phase-space of these models. Specifically, we express the thermodynamic quantities as functions of the phase-space variables, allowing us to study the thermodynamic behavior across the phase space, particularly at the critical points. We focus on thermodynamic stability and phase transitions, analyzed in an initial condition-independent manner. In these models, the universe inevitably undergoes a thermodynamic phase transition, marked by diverging specific heats, irrespective of its initial configuration. We further demonstrate that the thermodynamic stability can occur only during an accelerating phase of the universe. For <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <mi>Λ</mi>\u0000 <mi>CDM</mi>\u0000 </mrow>\u0000 <annotation>$Lambda{rm CDM}$</annotation>\u0000 </semantics></math> and quintessence models, the necessary stability conditions are never satisfied anywhere in the phase space, rendering both models thermodynamically unstable within the Hayward–Kodama framework and the canonical ensemble-based stability criteria. Interestingly, the phantom models, although dynamically unstable, allow for the universe to attain thermodynamic stability in its asymptotic future. This can indicate the limitations of applying canonical ensemble-based thermodynamic stability criteria to cosmological horizons. Through these archetypal descriptions of late-time cosmology, we show that the dynamical system approach is a robust framework to probe the thermodynamic aspects of cosmological evolution.</p>\u0000 </div>","PeriodicalId":55150,"journal":{"name":"Fortschritte Der Physik-Progress of Physics","volume":"74 4","pages":""},"PeriodicalIF":7.8,"publicationDate":"2026-03-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147585024","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":"Issue Information: Fortschritte der Physik 4 / 2026","authors":"","doi":"10.1002/prop.70103","DOIUrl":"https://doi.org/10.1002/prop.70103","url":null,"abstract":"","PeriodicalId":55150,"journal":{"name":"Fortschritte Der Physik-Progress of Physics","volume":"74 4","pages":""},"PeriodicalIF":7.8,"publicationDate":"2026-03-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/prop.70103","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147585287","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":"Hitchhiker's Guide to the Swampland: The Cosmologist's Handbook to the String-Theoretical Swampland Programme","authors":"Kay Lehnert","doi":"10.1002/prop.70073","DOIUrl":"https://doi.org/10.1002/prop.70073","url":null,"abstract":"<p>String theory has strong implications for cosmology, implying the absence of a cosmological constant, ruling out single-field slow-roll inflation, and that black holes decay. The origins of these statements are elucidated within the string-theoretical swampland programme. The swampland programme is generating a growing body of insights that have yet to be incorporated into cosmological models. Taking a cosmologist's perspective, the relevance of swampland conjectures to black holes, dark matter, dark energy, and inflation is highlighted, including their implications for scalar fields such as quintessence and axions. The aim is to inspire cosmological model builders to examine the compatibility of effective field theories with quantum gravitational UV completions and to address outstanding cosmological tensions such as the Hubble tension. This comprehensive literature review presents clear definitions, cosmological implications, and the current status — including evidence and counterexamples — of the following swampland conjectures: the <i>anti–de Sitter distance conjecture</i>, the <i>completeness conjecture</i>, the <i>cobordism conjecture</i>, the <i>de Sitter conjecture</i>, the <i>swampland distance conjecture</i>, the <i>emergence proposal</i>, the <i>Festina Lente Bound</i>, the <i>finite number of massless fields conjecture</i> (or <i>finite flux vacua conjecture</i>), the <i>no global symmetries conjecture</i>, the <i>no non-supersymmetric theories conjecture</i>, the <i>non-negative null energy condition conjecture</i>, the <i>positive Gauss–Bonnet term conjecture</i>, the <i>species scale conjecture</i>, the <i>gravitino swampland conjecture</i>, the <i>tadpole conjecture</i>, the <i>tameness conjecture</i>, the <i>trans–Planckian censorship conjecture</i>, the <i>unique geodesic conjecture</i>, and the <i>weak gravity conjecture</i>, including the <i>repulsive force conjecture</i>.</p>","PeriodicalId":55150,"journal":{"name":"Fortschritte Der Physik-Progress of Physics","volume":"74 4","pages":""},"PeriodicalIF":7.8,"publicationDate":"2026-03-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/prop.70073","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147615397","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}