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2606.19466 2026-06-19 physics.gen-ph 新提交

Non-degenerate and degenerate wormholes: a unified approach

非退化与退化虫洞:一种统一方法

Juri Dimaschko

AI总结 引入广义退化虫洞概念,通过g²修正爱因斯坦场方程统一描述非退化与退化虫洞,揭示爱因斯坦-罗森桥与Klinkhamer缺陷虫洞为真空解,并指出经典零能量条件定理仅适用于非退化情形。

Comments Accepted for publication in Modern Physics Letters A

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AI中文摘要

引入广义退化虫洞概念,定义为虫洞喉部度量行列式g为零。它由多项式g²修正的爱因斯坦场方程描述。基于此框架,我们证明爱因斯坦-罗森桥和Klinkhamer缺陷虫洞都是g²修正方程的精确真空解,全局有效,包括在退化喉部,而Klinkhamer构型还允许b>2M的可穿越几何,其中b设定虫洞喉部的长度尺度,M是质量参数。相比之下,由常规(非正则化)爱因斯坦方程支配的标准Morris-Thorne虫洞和薄壳虫洞本质上是非退化的,并且必须由奇异应力-能量支撑。在带有物质场的统一正则化系统中,薄壳虫洞和Klinkhamer虫洞表现为两种性质不同的状态类别:非退化且带有奇异物质,与退化且真空共享爱因斯坦-罗森桥作为共同极限构型。这种统一观点阐明了经典零能量条件不可行定理为何仅适用于非退化部分,并暗示了不需要违反NEC的稳态可穿越退化虫洞的可能性。

英文摘要

A generalized notion of degenerate wormholes is introduced, defined by the vanishing of the metric determinant g at the throat. It is described by the polynomial, g^2 modified Einstein field equations. Building on this framework, we show that both the Einstein Rosen bridge and the Klinkhamer defect wormhole are exact vacuum solutions of the g^2 modified equations, valid globally including at the degenerate throat, while the Klinkhamer configuration additionally admits traversable geometries with b>2M, where b sets the length scale of the wormhole throat and M is a mass parameter. In contrast, standard Morris Thorne and thin shell wormholes, governed by the conventional (non regularized) Einstein equations, are intrinsically non degenerate and necessarily supported by exotic stress energy. Within a unified regularized system with matter, both thin shell and Klinkhamer wormholes appear as two qualitatively distinct classes of states: non degenerate with exotic matter versus degenerate with vacuum sharing the Einstein Rosen bridge as a common limiting configuration. This unified viewpoint clarifies why classical null energy condition no go theorems apply only to the non degenerate sector and suggests the possibility of stationary degenerate traversable wormholes that do not require NEC violation.

2606.19402 2026-06-19 physics.gen-ph 新提交

Cosmic Structure Formation in a Viable Power-Law f(R) Gravity Model: Growth Dynamics, Stability, and Observational Signatures

可行幂律 f(R) 引力模型中的宇宙结构形成:增长动力学、稳定性与观测特征

Murli Manohar Verma

AI总结 研究幂律修正f(R)引力模型中的宇宙结构形成,通过推导修正扰动方程和分析增长因子等,发现曲率修正增强物质扰动增长,模型满足理论稳定性条件,并预测了可被未来巡天检验的观测特征。

Comments 15 Pages, 2 Figures, 8 Tables

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AI中文摘要

我们研究了幂律修正引力模型 $f(R)=R+R^{1+\delta}/R_c^\delta$ 中宇宙结构的演化,其中无量纲参数 $\delta$ 表征与广义相对论的偏离。在度规 $f(R)$ 引力框架下,研究了背景宇宙学动力学和线性物质密度扰动的演化。通过引入与额外标量自由度相关的有效引力耦合,推导了修正的扰动方程,并研究了增长因子、对数增长率、增长指数以及可观测物理量 $f\sigma_8(z)$ 的演化。结果表明,曲率修正增强了物质扰动的增长,同时对于合适的模型参数值,与观测到的晚期加速膨胀相容。通过无鬼条件、Dolgov-Kawasaki稳定性判据、正标量场质量、稳定的德西特解以及变色龙屏蔽机制,确立了模型的理论可行性。与代表性的可行 $f(R)$ 引力模型比较表明,本理论通过单一偏差参数实现了一致的宇宙学演化。预测的结构增长和有效引力耦合的变化提供了可观测特征,可由即将进行的大尺度结构和弱引力透镜巡天检验,从而提供检验曲率修正引力的手段。

英文摘要

We investigate the evolution of cosmic structures in the power-law modified gravity model $f(R)=R+R^{1+δ}/R_c^δ$, where the dimensionless parameter $δ$ characterizes deviations from General Relativity. The background cosmological dynamics and the evolution of linear matter density perturbations are studied within the framework of metric $f(R)$ gravity. The modified perturbation equation is derived by introducing an effective gravitational coupling associated with the additional scalar degree of freedom, and the evolution of the growth factor, logarithmic growth rate, growth index, and the observable quantity $fσ_8(z)$ are investigated. The results show that the curvature correction enhances the growth of matter perturbations while remaining compatible with the observed late-time accelerated expansion for suitable values of the model parameter. The theoretical viability of the model is established through the ghost-free condition, Dolgov--Kawasaki stability criterion, positive scalaron mass, stable de Sitter solution, and chameleon screening mechanism. Comparison with representative viable $f(R)$ gravity models shows that the present theory achieves a consistent cosmological evolution with a single deviation parameter. The predicted modifications in the growth of structures and the effective gravitational coupling provide observable signatures that can be tested by forthcoming large-scale structure and weak-lensing surveys, providing a means to test curvature-induced modifications of gravity.

2604.24795 2026-06-19 physics.gen-ph 版本更新

Higgs and Yukawa Structure in a Clifford Algebra Model with Three Generations and $S_3$ Family Symmetry

Clifford代数模型中三代与$S_3$族对称性的Higgs和Yukawa结构

Niels Gresnigt

AI总结 基于Clifford代数与S3族对称性,构建了包含两个Higgs双重态和Type-II类Yukawa结构的代数三代模型,通过右作用算子和Hilbert-Schmidt迹提取Yukawa系数,在循环平均极限下避免了树级味道改变中性流。

Comments 28 pages

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AI中文摘要

我们构建了Higgs和Yukawa扇区,作为基于复Clifford代数$\mathbb{C}\ell(10)$且具有内禀$S_3$族对称性的代数三代模型的结构补充。这解决了代数框架的一个常见局限,即标准模型费米子多重态和规范对称性可以自然描述,而Higgs和Yukawa扇区则发展不足或缺失。在当前框架中,三个代数上区分的费米子扇区由$S_3$置换,而标准模型规范生成元保持与代无关。Higgs分量被实现为右作用算子,将弱双重态费米子扇区映射到相应的弱单态扇区,并使用Hilbert-Schmidt迹配对提取Yukawa系数。这产生了两个具有电弱量子数$(1,2,-1)$和$(1,2,+1)$(在$SU(3)_C \times SU(2)_L \times U(1)_Y$下)的第一代Higgs双重态,以及一个类Type-II的下型和上型Yukawa通道分离。作用三阶族生成元则生成一个按循环$S_3$轨道组织的族分辨Higgs扇区。在循环平均的Higgs极限下,类Type-II的Yukawa选择规则得以保持,而代空间的Yukawa矩阵被代数固定,且在代数生成基下非对角。在通常的电弱对称性破缺实现下,中性Higgs耦合与相应的质量矩阵对齐,因此在此极限下预期不会出现树级味道改变中性流。结果为未来$S_3$破缺的味道现象学提供了一个受约束的代数起点。

英文摘要

We construct the Higgs and Yukawa sectors as a structural completion of an algebraic three-generation model based on the complex Clifford algebra $\mathbb{C}\ell(10)$ with an intrinsic $S_3$ family symmetry. This addresses a common limitation of algebraic frameworks, in which Standard Model fermion multiplets and gauge symmetries may be described naturally, while the Higgs and Yukawa sectors remain less developed or absent. In the present framework, three algebraically distinguished fermion sectors are permuted by $S_3$, while the Standard Model gauge generators remain generation-independent. Higgs components are realised as right-action operators mapping weak-doublet fermion sectors into the corresponding weak-singlet sectors, and Yukawa coefficients are extracted using a Hilbert--Schmidt trace pairing. This yields two first-generation Higgs doublets with electroweak quantum numbers $(1,2,-1)$ and $(1,2,+1)$ under $SU(3)_C \times SU(2)_L \times U(1)_Y$, together with a Type-II-like separation between down-type and up-type Yukawa channels. Acting with the order-three family generator then generates a family-resolved Higgs sector organised into cyclic $S_3$ orbits. In the cyclically averaged Higgs limit, the Type-II-like Yukawa selection rule is preserved, while the generation-space Yukawa matrix is fixed algebraically and is non-diagonal in the algebraic generation basis. Under the usual implementation of electroweak symmetry breaking, the neutral Higgs couplings are aligned with the corresponding mass matrices, so tree-level flavour-changing neutral currents are not expected in this limit. The result is a constrained algebraic starting point for future $S_3$-breaking flavour phenomenology.

2411.16777 2026-06-19 physics.gen-ph 版本更新

Equivalence between the zero distributions of the Riemann zeta function and a two-dimensional Ising model with randomly distributed competing interactions

Zhidong Zhang

Comments 44 pages, 0 figure, discussion and references are added

Journal ref Phys. Lett. A (2026) 131910

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英文摘要

In this work, we prove the equivalence between the zero distributions of the Riemann zeta function ζ(s) and a two-dimensional (2D) Ising model with a mixture of ferromagnetic and randomly distributed competing interactions. At first, we review briefly the characteristics of the Riemann hypothesis and its connections to physics, in particular, to statistical physics. Second, we build a 2D Ising model, M_(FI+SGI)^2D, in which interactions between the nearest neighboring spins are ferromagnetic along one crystallographic direction while competing ferromagnetic/antiferromagnetic interactions are randomly distributed along another direction. Third, we prove that all energy eigenvalues of this 2D Ising model M_(FI+SGI)^2D are real and randomly distributed as the Möbius function μ(n), the Dirichlet L(s,\c{hi}_k ) function as well as the Riemann zeta function ζ(s). Fourth, we prove that the eigenvectors of the 2D Ising model M_(FI+SGI)^2D are constructed by the eigenvectors of the 1D Ising model with phases related to the Riemann zeta function ζ(s), via the relation ω(γ_2j) between the angle ω and the energy eigenvalues γ_2j, which form the Hilbert-Pólya space. Fifth, we prove that all the zeros of the partition function of the 2D Ising model M_(FI+SGI)^2D lie on an unit circle in a complex temperature plane (i.e. Fisher zeros), which can be mapped to the zero distribution of the Dirichlet L(s,\c{hi}_k ) function and also the Riemann zeta function ζ(s) in the critical line. In a conclusion, we have proven the closure of the nontrivial zero distribution of the L(s,\c{hi}_k ) function (including the Riemann zeta function ζ(s)).