REVIEW 1 major objections 5 minor 76 references
Intrinsic Torsion, Extrinsic Torsion, and the Hubble Parameter
T0 review · 1 major / 5 minor · reviewed 2026-08-11 · deepseek-v4-flash
Pith's one-line read Extrinsic torsion inevitably mixes with the Hubble parameter in metric-compatible torsional theories, and ignoring it makes inferred expansion rates too small.
desk verdict The paper's real contribution is a clean, apparently correct geometric identity that mixes the Hubble parameter with extrinsic torsion in the generalized Friedmann constraint; the Hubble-anomaly application rests entirely on an unproven tracking conjecture and is not established. read the letter →
The pith
A machine-rendered reading of the paper's core claim, the machinery that carries it, and where it could break.
The reading
What carries the argument
The central object is the torsional Gauss-Codazzi equation, $T^*(X,Y)=T(X,Y)+\alpha(X,Y)-\alpha(Y,X)$, which defines intrinsic torsion $T$ and extrinsic torsion $\alpha(X,Y)-\alpha(Y,X)$. Combined with the second fundamental form decomposition $h=\tfrac12 \mathcal{L}_\xi g^* + \tfrac12 \kappa$, where $\kappa$ is the extrinsic torsion two-form, it shows that the antisymmetric part of the second fundamental form is exactly the extrinsic torsion. This identity is what carries the argument: it puts $H$ and $\kappa$ on equal footing in the generalized Friedmann constraint.
What would settle it
Take one cosmic epoch and measure $\rho$, the intrinsic scalar curvature $\mathrm{Scal}$, and $H$ independently; in Einstein-Cartan theory the residual $16\pi G\rho/c^4 - \mathrm{Scal} - 6H^2$ must equal $-\kappa^2/2$, so a positive residual, or a zero residual where independent spin-density bounds force $\kappa=0$, would rule out the mechanism.
Extended reading notes
Core claim
The paper's central claim is that torsion has an extrinsic face that cannot be ignored. Splitting the spacetime torsion into terms tangential and normal to a spacelike hypersurface gives $T^*(X,Y)=T(X,Y)+\alpha(X,Y)-\alpha(Y,X)$, so the antisymmetric part of the second fundamental form is literally the extrinsic torsion. Because the second fundamental form also carries the Hubble parameter, the geometry forces a mixing: $h=\tfrac12 \mathcal{L}_\xi g^* + \tfrac12 \kappa$. Feeding this into the Gauss equation and the Einstein-Cartan field equations yields $16\pi G\rho/c^4=\mathrm{Scal}+6H^2-\tfrac12 \kappa^2$, with $H^2$ and $\kappa^2$ entering with opposite signs. The paper argues that the same combination survives in any metric-compatible torsional theory, and that inflation can naturally make $\kappa$ of order $H$ at reheating while wiping out the intrinsic torsion. It stops short of claiming to solve the Hubble tension, but asserts that extrinsic torsion is the most natural geometric source of Hubble-parameter anomalies.
Load-bearing premise
The whole mechanism depends on torsion 'tracking' curvature during inflation: what makes spatial curvature shrink must also make the twist of space into spacetime grow; if torsion does not follow curvature in this way, the extrinsic torsion could remain zero or negligible even at reheating.
Editorial extensions
If this is right
- Any metric-compatible torsional theory has $h = \tfrac12 \mathcal{L}_\xi g^* + \tfrac12 \kappa$, so the Hubble parameter and extrinsic torsion are inseparable in the second fundamental form.
- In Einstein-Cartan theory the generalized Friedmann constraint is $16\pi G\rho/c^4 = \mathrm{Scal} + 6H^2 - \tfrac12 \kappa^2$; an observer setting $\kappa=0$ infers an $H$ that is too small.
- If intrinsic torsion tracks intrinsic curvature during inflation, then extrinsic torsion can grow to order $H$ by reheating, producing percent-level corrections to the theoretical Hubble parameter.
- Fully isotropic spatial sections have identically zero extrinsic torsion, so nonzero extrinsic torsion at late times requires anisotropic pre-inflationary initial data.
- The mixing is generic across torsional theories with zero non-metricity, not an artifact of Einstein-Cartan theory.
Reading between the lines
- A precision measurement of $16\pi G\rho/c^4 - \mathrm{Scal} - 6H^2$ at a single epoch would directly bound $\kappa^2$; a negative residual would be a clean torsion signature, since no standard-matter contribution produces that sign in this combination.
- The paper's 'torsion escarpment' phenomenon suggests that gravitational-wave or tensor-harmonic surveys should look for large geodesic deviations sourced by small but rapidly changing torsion, a signature that curvature alone cannot produce.
- If torsional inflation can start from anisotropic initial data with large intrinsic torsion, the usual causality-based obstruction to inflation onset may fail; redoing that no-go argument with torsion is a concrete theoretical next step.
- The same geometric mixing should apply around static compact objects: in a torsional Schwarzschild-like solution the extrinsic torsion does not vanish even though the Hubble term does, so solar-system tests of spatial geometry could probe torsion independently of cosmology.
Editorial analysis
A structured set of objections, weighed in public.
Referee Report
Summary. The paper develops a geometric framework for intrinsic and extrinsic torsion of spacelike hypersurfaces in metric-compatible torsional spacetimes. It derives the torsional Gauss-Codazzi equation (11), the decomposition of the second fundamental form into a Hubble-related symmetric part and an extrinsic-torsion antisymmetric part (26), and, in Einstein-Cartan theory, a generalized Friedmann constraint (37) in which the Hubble parameter H and the extrinsic torsion parameter κ mix with opposite signs. It then conjectures that during inflation the intrinsic torsion tracks the intrinsic Levi-Civita curvature and inflates away, while the extrinsic torsion tracks the extrinsic curvature and inflates up, leading to a possible underestimate of the Hubble parameter if extrinsic torsion is ignored.
Significance. The purely geometric identities, especially Eq (26) and the decomposition of the second fundamental form, are clean, clearly derived, and likely useful for future work on torsional cosmology. The paper is commendably explicit about the distinction between the derived identities and the speculative dynamical assumptions. However, the central quantitative conclusion (the 4% Hubble underestimate) is not established: it rests on an unproven tracking conjecture that is not supported by any field equations or explicit model, and the paper itself shows that in fully isotropic sections the extrinsic torsion remains exactly zero. The significance of the work is therefore that of a well-formulated possibility, not a derivation of an observable effect.
major comments (1)
- [Section 4.2 (tracking conjecture)] The quantitative Hubble-parameter claim is not derived. The paragraph beginning 'It seems natural, however, to assume...' asserts that if intrinsic torsion tracks intrinsic Levi-Civita curvature, then extrinsic torsion tracks extrinsic Levi-Civita curvature, and the following 'concrete example' stipulates κ ≈ H at reheating. No field equations, evolution equations, or explicit torsional inflationary model are provided to support this tracking behaviour. This assumption is load-bearing because if κ decays during inflation or remains negligible, Eq (37) reduces to the standard Friedmann equation and the claimed anomaly disappears. The paper itself shows (Section 4.2, after Eq (40)) that in the fully isotropic case the extrinsic torsion is zero at all times; the proposed resolution, namely anisotropic pre-inflationary sections, is not realized by any concrete example. The 4% underestimate should therefore be presented as an illustrative possibility, not as a prediction, unless a supporting model is supplied.
minor comments (5)
- [Section 4.2, p. 23] The statement that 'H and κ will appear in the same combination even in such theories' is stronger than the derivation supports: Eq (37) is obtained from the Einstein-Cartan field equations (28)-(29), whereas the universal geometric result is Eq (26). Please restrict the generality claim to Eq (26) or provide a proof for a broader class of theories.
- [Section 4.2, Eq (35)] The symbol κ is used both for the two-form in Eq (25) and for the real parameter introduced after Eq (35); this reuse is potentially confusing, and a distinct notation (e.g., κ₀) would improve readability.
- [Abstract] The phrase 'extrinsic torsion is by far the most natural way to produce such anomalies' is a subjective assertion not accompanied by a comparison with other proposed mechanisms for Hubble-parameter anomalies; consider softening it.
- [Title page] The title currently displays stray spaces ('Intrinsic T orsion, Extrinsic T orsion'); these should be corrected in the final typeset version.
- [Section 3.2, after Eq (11)] The statement that torsion 'cannot be cancelled' by manipulating α is too absolute: Eq (11) shows the normal part of T* can be cancelled by an antisymmetric α, and cancellation is prevented only by the tangential part of T*. Suggest replacing 'cannot' with 'cannot in general'.
Circularity Check
No significant circularity: Eq. (26) and Eq. (37) are derived from definitions and the Einstein-Cartan field equations, and the Hubble-underestimate estimate is explicitly conditional on a labeled tracking postulate rather than a fitted or self-referential prediction.
full rationale
The central derivation chain is self-contained. Equation (26) is obtained in Appendix 1 from the definition of the second fundamental form and metric compatibility; it is an identity, not a fit. Equation (37) is derived from the Einstein-Cartan field equation (28) together with the Gauss equation (14), so the appearance of 6H^2 - (1/2)kappa^2 is a consequence of the stated assumptions rather than an input. The quantitative Hubble-anomaly statement in Sec. 4.2 is explicitly conditional: the paper postulates that intrinsic torsion 'tracks' intrinsic Levi-Civita curvature and inflates away, and that extrinsic torsion then 'tracks' extrinsic Levi-Civita curvature and inflates up; this is labeled as 'we postulate' and 'It seems natural, however, to assume', and the paper itself notes that in the fully isotropic case (Eqs. (39)-(40)) the extrinsic torsion remains zero at all times, so the mechanism is not automatic. The 4% underestimate is therefore an illustrative stipulation rather than a derived prediction, and underdetermination is not circularity. The only self-citation ([58]) appears in an aside offering a possible topological explanation of small intrinsic curvature and is not load-bearing for the paper's main claims. No fitted input is renamed as a prediction, and no load-bearing assertion is justified solely by a self-citation.
Assumptions & free parameters
free parameters (1)
- tracking ratio r = kappa/H at reheating =
r approximately 1 (illustrative example)
assumptions (3)
- domain assumption The spacetime connection is metric-compatible (zero non-metricity).
- ad hoc to paper The pre-inflationary spatial sections are sufficiently anisotropic to support a non-zero intrinsic torsion.
- standard math The Gauss-Codazzi equations (11), (13), (14) extend unchanged to metric-compatible connections with torsion.
Cite this review
Pith. "Pith review of Intrinsic Torsion, Extrinsic Torsion, and the Hubble Parameter." pith.science (2026). https://pith.science/paper/W7H3PS5N
@misc{pith2026241208990,
author = {Pith},
title = {Pith review of: Intrinsic Torsion, Extrinsic Torsion, and the Hubble Parameter},
year = {2026},
howpublished = {\url{https://pith.science/paper/W7H3PS5N}},
note = {Machine review of arXiv:2412.08990}
}
abstract
We study the intrinsic and extrinsic torsions (defined by analogy with the intrinsic and extrinsic curvatures) of the spatial sections of torsional spacetimes. We consider two possibilities. First, that the intrinsic torsion might prove to be directly observable. Second, that it is not observable, having been ``inflated away'' in the early Universe. We argue that, even in this second case, the extrinsic torsion may grow during the inflationary era and be non-negligible at reheating and thereafter. Even if the spatial intrinsic curvature and torsion are too small to be detected directly, then, the extrinsic torsion might not be. We point out that, if its presence is not recognised, the extrinsic torsion could lead to anomalies in the theoretical estimate of the Hubble parameter -- $\,$ a result with obvious potential applications. We stress that extrinsic torsion is by far the most natural way to produce such anomalies, simply because it mixes naturally with the Hubble parameter; that is, the second fundamental form of a spacelike section depends on a sum of two terms, one determined by the Hubble parameter, the other by the extrinsic torsion.
Reference graph
Works this paper leans on
-
[1]
Breitenberger, E., Gauss’s geodesy and the axiom of para llels, Arch. Rational Mech. 31, 273 - 289 (1984)
work page 1984
-
[2]
J. E. Beichler, Degaussing Miller’s Myth: A reappraisal of Gauss’ experiment to determine space curvature, Schuman Competition Essay (199 2)
-
[3]
Michael Marder, Robert D. Deegan, Eran Sharon, Crumplin g, buckling, and cracking: Elasticity of thin sheets, Physics Today 60 (2), 33 - 38 (2007 )
work page 2007
-
[4]
Deegan, Eran Sharon, Gauss on t he mountaintops, Physics Today 61 (2), 13 (2008)
Michael Marder, Robert D. Deegan, Eran Sharon, Gauss on t he mountaintops, Physics Today 61 (2), 13 (2008)
work page 2008
- [5]
-
[6]
Schwarzschild, On the permissible curvature of space , Class
K. Schwarzschild, On the permissible curvature of space , Class. Quantum Grav. 15 (1998) 2539
work page 1998
-
[7]
Wei-Tou Ni, Space gravitational wave detection: Progre ss and outlook, Sci Sin-Phys Mech Astron, 2024, 54: 270402, arXiv:2409.00927 [gr-qc]
arXiv 2024
-
[8]
Alisha Marriott-Best, Debika Chowdhury, Anish Ghoshal , Gianmassimo Tasinato, Exploring cosmological gravitational wave backgrounds th rough the synergy of LISA and ET, arXiv:2409.02886 [astro-ph.CO] 32
Show all 76 references
-
[9]
Valerie Domcke, Discovery Opportunities with Gravitat ional Waves – TASI 2024 Lecture Notes, arXiv:2409.08956 [astro-ph.CO]
2024 arXiv
-
[10]
Jose María Ezquiaga, Miguel Zumalacárregui, Dark Ener gy after GW170817: dead ends and the road ahead, Phys. Rev. Lett. 119, 251304 (2017), arXiv:1710.05901 [astro-ph.CO]
2017 arXiv
-
[11]
Daniel Blixt, Alejandro Jiménez Cano, Aneta Wojnar, Fo liation-generating observers under Lorentz transformations, Symmetry 16 (2024) 10, 1384 , arXiv:2408.16513 [gr- qc]
2024 arXiv
-
[12]
Hehl, Gauge Theories of Gravitation, arXiv:1210.3775 [gr-qc]
Milutin Blagojević, Friedrich W. Hehl, Gauge Theories of Gravitation, arXiv:1210.3775 [gr-qc]
-
[13]
Sebastian Bahamonde, Konstantinos F. Dialektopoulos , Celia Escamilla-Rivera, Gabriel Farrugia, Viktor Gakis, Martin Hendry, Manuel Hohm ann, Jackson Levi Said, Jurgen Mifsud, Eleonora Di Valentino, Teleparallel G ravity: From Theory to Cosmology, Rept.Prog.Phys. 86 (2023) 2, ...
2023
-
[14]
Mavromatos, Pablo Pais, Alfredo Iorio, Torsion at different scales: from materials to the Universe, Universe 2023, 9(12), 516, arXiv :2310.13150 [gr-qc]
Nick E. Mavromatos, Pablo Pais, Alfredo Iorio, Torsion at different scales: from materials to the Universe, Universe 2023, 9(12), 516, arXiv :2310.13150 [gr-qc]
2023 arXiv
-
[15]
Nester, Pisin Chen , Problems with Prop- agation and Time Evolution in f(T) Gravity, Phys
Yen Chin Ong, Keisuke Izumi, James M. Nester, Pisin Chen , Problems with Prop- agation and Time Evolution in f(T) Gravity, Phys. Rev. D 88, 0 24019 (2013), arXiv:1303.0993 [gr-qc]
2013 arXiv
-
[16]
69 (2024) 7, 456, arXiv:2405.14184 [gr-qc]
Alexey Golovnev, Degrees of Freedom in modified Telepar allel Gravity, Ukr.J.Phys. 69 (2024) 7, 456, arXiv:2405.14184 [gr-qc]
2024 arXiv
-
[17]
Marco Cirelli, Alessandro Strumia, Jure Zupan, Dark Ma tter, arXiv:2406.01705 [hep- ph]
-
[18]
Streit-Bianchi & V
Sergio Luigi Cacciatori, Vittorio Gorini, Federico Re , Dark Matter, New Frontiers in Science in the Era of AI, edited by M. Streit-Bianchi & V. Gori ni, 2024, Springer, arXiv:2410.10424 [gr-qc]
2024 arXiv
-
[19]
José Barrientos, Fabrizio Cordonier-Tello, Cristóba l Corral, Fernando Izaurieta, Perla Medina, Eduardo Rodríguez, Omar Valdivia, Luminal Propaga tion of Gravitational Waves in Scalar-tensor Theories: The Case for Torsion, Phys . Rev. D 100, 124039 (2019), arXiv:1910.00148 [gr-qc]
2019 arXiv
-
[20]
Elizalde, F
E. Elizalde, F. Izaurieta, C. Riveros, G. Salgado, O. Va ldivia, Gravitational Waves in Einstein-Cartan Theory: On the Effects of Dark Matter Spin Tensor, Phys.Dark Univ. 40 (2023) 101197, arXiv:2204.00090 [gr-qc]
2023 arXiv
-
[21]
Vittorio De Falco, Emmanuele Battista, Davide Ussegli o, Salvatore Capozziello, Ra- diative losses and radiation-reaction effects at the first po st-Newtonian order in Einstein-Cartan theory, Eur.Phys.J.C 84 (2024) 2, 137, arX iv:2401.13374 [gr-qc] 33
2024 arXiv
-
[22]
Alberto Salvio, Inflating and reheating the Universe wi th an independent affine con- nection, Phys.Rev.D 106 (2022) 10, 103510, arXiv:2207.088 30 [hep-ph]
2022
-
[23]
Gialamas, Kyriakos Tamvakis, Inflation in Me tric-Affine Quadratic Grav- ity, JCAP 03 (2023) 042, arXiv:2212.09896 [gr-qc]
Ioannis D. Gialamas, Kyriakos Tamvakis, Inflation in Me tric-Affine Quadratic Grav- ity, JCAP 03 (2023) 042, arXiv:2212.09896 [gr-qc]
2023 arXiv
-
[24]
Gialamas, Hardi Veermäe, Electroweak vacuu m decay in metric-affine gravity, Phys.Lett.B 844 (2023) 138109, arXiv:2305.07693 [hep-th]
Ioannis D. Gialamas, Hardi Veermäe, Electroweak vacuu m decay in metric-affine gravity, Phys.Lett.B 844 (2023) 138109, arXiv:2305.07693 [hep-th]
2023 arXiv
-
[25]
Alberto Salvio, Inflation and Reheating through an Inde pendent Affine Connection, arXiv:2311.02902 [hep-ph]
-
[26]
Antonio Racioppi, Alberto Salvio, Natural metric-affin e inflation, JCAP 06 (2024) 033, arXiv:2403.18004 [hep-ph]
2024 arXiv
-
[27]
Baldazzi, O
A. Baldazzi, O. Melichev, R. Percacci, Metric-Affine Gra vity as an effective field theory, Annals Phys. 438 (2022) 168757, arXiv: 2112.10193 [ gr-qc]
2022 arXiv
-
[28]
Dragan Huterer, Specific Effect of Peculiar Velocities o n Dark-Energy Constraints from Type Ia Supernovae, Astrophys. J. Lett. 904, L28 (2020) , arXiv:2010.05765 [astro-ph.CO]
2020 arXiv
-
[29]
Utkarsh Kumar, Udaykrishna Thattarampilly, Pankaj Ch aturvedi, Probe of spatial geometry from scalar induced gravitational waves, arXiv:2 410.12931 [astro-ph.CO]
-
[30]
Taylor, Fan Zhang, Scalar, Ve ctor and Tensor Harmonics on the Three-Sphere, Gen.Rel.Grav
Lee Lindblom, Nicholas W. Taylor, Fan Zhang, Scalar, Ve ctor and Tensor Harmonics on the Three-Sphere, Gen.Rel.Grav. 49 (2017) 11, 139, arXiv :1709.08020 [gr-qc]
2017 arXiv
-
[31]
Copi, Johanne s R
Yashar Akrami, Stefano Anselmi, Craig J. Copi, Johanne s R. Eskilt, Andrew H. Jaffe, Arthur Kosowsky, Pip Petersen, Glenn D. Starkman, Kev in González-Quesada, Özenç Güngör, Deyan P. Mihaylov, Samanta Saha, Andrius Tamo siunas, Quinn Tay- lor, Valeri Vardanyan (COMPACT Collabor...
2024 arXiv
-
[32]
5-6 (2014) 75-235, arXiv:1303.3787v4 [ast ro-ph.CO]
Jerome Martin, Christophe Ringeval, Vincent Vennin, E ncyclopaedia Inflationaris, Phys.Dark Univ. 5-6 (2014) 75-235, arXiv:1303.3787v4 [ast ro-ph.CO]
2014 arXiv
-
[33]
Alexey Golovnev, Is there any Trinity of Gravity, to sta rt with?, arXiv:2411.14089 [gr-qc]
-
[34]
Obukhov, Friedrich W
Yuri N. Obukhov, Friedrich W. Hehl, Violating Lorentz i nvariance minimally by the emergence of nonmetricity? A Perspective, Annalen Phys . (2024) 2400217, arXiv:2409.19411 [gr-qc]
2024 arXiv
-
[35]
133 (20 24) 7, 071501, 2402.06009 [astro-ph.HE]
LHAASO Collaboration, Stringent Tests of Lorentz Inva riance Violation from LHAASO Observations of GRB 221009A, Phys.Rev.Lett. 133 (20 24) 7, 071501, 2402.06009 [astro-ph.HE]
-
[36]
S Kobayashi and K Nomizu, Foundations of Differential Geometry II , Interscience, New York (1969) 34
1969
-
[37]
J L Synge, Relativity: the General Theory Amsterdam: North-Holland, 1961
1961
-
[38]
Santana, Maurício O
Lucas T. Santana, Maurício O. Calvão, Ribamar R. R. Reis , Beatriz B. Siffert, How does light move in a generic metric-affine background?, Ph ysical Review D 95, 061501(R) (2017), arXiv:1703.10871 [gr-qc]
2017 arXiv
-
[39]
Paulo Luz, José P. S. Lemos, Relativistic cosmology and intrinsic spin of matter: Results and theorems in Einstein-Cartan theory, Phys. Rev. D 107, 084004 (2023), arXiv:2303.03104 [gr-qc]
2023 arXiv
-
[40]
Armin van de Venn, Ujjwal Agarwal, David Vasak, Road to S ingularity Theorems with Torsion, Phys. Rev. D 110, 064082 (2024), arXiv:2407.2 1107 [gr-qc]
2024
-
[41]
Kranas, C.G
D. Kranas, C.G. Tsagas, J.D. Barrow, D. Iosifidis, Fried mann-like universes with torsion, Eur.Phys.J.C 79 (2019) 4, 341, arXiv:1809.10064 [ gr-qc]
2019 arXiv
-
[42]
496 (2020) 1, L91-L95, arXiv:200 2.06892 [astro-ph.CO]
George Efstathiou, Steven Gratton, The evidence for a s patially flat Universe, Mon.Not.Roy.Astron.Soc. 496 (2020) 1, L91-L95, arXiv:200 2.06892 [astro-ph.CO]
2020
-
[43]
Yang Hu, Suhail Dhawan, Constrain Spatial Curvature an d Dark Energy with Strong Lenses and Complementary Probes: a Forecast for Next -Generation Surveys, arXiv:2411.05082
-
[44]
Mariana L. S. Dias, Antônio F. B. da Cunha, Carlos A. P. Be ngaly, Rodrigo S. Gonçalves, Jonathan Morais, Non-parametric reconstructi ons of cosmic curvature: current constraints and forecasts, arXiv:2411.19252 [ast ro-ph.CO]
-
[45]
D 100 (2019) 8, 084002, arXiv:1901.05472 [gr-qc]
Manuel Hohmann, Laur Järv, Martin Krššák, Christian Pf eifer, Modified teleparal- lel theories of gravity in symmetric spacetimes, Phys.Rev. D 100 (2019) 8, 084002, arXiv:1901.05472 [gr-qc]
2019 arXiv
-
[46]
A. A. Coley, R. J. van den Hoogen, D. D. McNutt, Symmetric Teleparallel Geome- tries, Class. Quantum Grav., 39, 22LT01 (2022), arXiv:2205 .10719 [gr-qc]
2022
-
[47]
McNutt, Alan A
David D. McNutt, Alan A. Coley, Robert J. van den Hoogen, Symmetries in Riemann-Cartan Geometries, SIGMA 20 (2024), 078, arXiv:24 01.00780 [gr-qc]
2024
-
[48]
D. D. McNutt, R. J. van den Hoogen, A. A. Coley, Locally-h omogeneous Riemann- Cartan geometries with the largest symmetry group, J. Math. Phys. 65, 072502 (2024), arXiv:2401.02907 [gr-qc]
2024 arXiv
-
[49]
Providence: American Mathematical Society (2012)
Teschl, Gerald, Ordinary Differential Equations and Dy namical Systems. Providence: American Mathematical Society (2012)
2012
-
[50]
Symmetry, 9(7), 112 (201 7)
Li, J., He, G., Zhao, P., On Submanifolds in a Riemannian Manifold with a Semi- Symmetric Non-Metric Connection. Symmetry, 9(7), 112 (201 7)
-
[51]
46 (2024) 101596, arXiv:2402.06114 [gr-qc] 35
Lehel Csillag, Tiberiu Harko, Semi-symmetric metric g ravity: From the Friedmann- Schouten geometry with torsion to dynamical dark energy mod els, Phys.Dark Univ. 46 (2024) 101596, arXiv:2402.06114 [gr-qc] 35
2024 arXiv
-
[52]
Himanshu Chaudhary, Lehel Csillag, Tiberiu Harko, Sem i-Symmetric Metric Gravity: A Brief Overview, Universe 10 (2024) 11, 419, arXiv:2411.03 060 [gr-qc]
2024
-
[53]
14, 099 (2023), arXiv:2211.02064 [hep-th] [a stro-ph.CO]
Johanna Erdmenger, Bastian Heß, Ioannis Matthaiakaki s, René Meyer, Universal Gibbons-Hawking-York term for theories with curvature, to rsion and non-metricity, SciPost Phys. 14, 099 (2023), arXiv:2211.02064 [hep-th] [a stro-ph.CO]
2023 arXiv
-
[54]
Freedman, Barry F
Wendy L. Freedman, Barry F. Madore, In Sung Jang, Taylor J. Hoyt, Abigail J. Lee, Kayla A. Owens, Status Report on the Chicago-Carnegie Hubbl e Program (CCHP): Three Independent Astrophysical Determinations of the Hub ble Constant Using the James Webb Space Telescope, arXiv:24...
-
[55]
Gibbons, S.N
G.W. Gibbons, S.N. Solodukhin, The Geometry of Large Ca usal Diamonds and the No Hair Property of Asymptotically de-Sitter Spacetimes, P hys.Lett.B 652 (2007) 103-110, arXiv:0706.0603 [hep-th]
2007 arXiv
-
[56]
1022 (2023) 1-82, arXiv:2303.08802 [hep-th]
Jean-Luc Lehners, Review of the no-boundary wave funct ion, Phys.Rept. 1022 (2023) 1-82, arXiv:2303.08802 [hep-th]
2023 arXiv
-
[57]
Penrose, Singularities and Time-Asymmetry, in Gene ral Relativity: An Einstein Centenary Survey, eds S W Hawking, W Israel, Cambridge Unive rsity Press, 1979
R. Penrose, Singularities and Time-Asymmetry, in Gene ral Relativity: An Einstein Centenary Survey, eds S W Hawking, W Israel, Cambridge Unive rsity Press, 1979
1979
-
[58]
Brett McInnes, Arrow of time in string theory, Nucl.Phy s.B 782 (2007) 1-25, arXiv:hep-th/0611088 [hep-th]
2007 arXiv
-
[59]
Carroll, In What Sense Is the Early Universe Fine -Tuned?, arXiv:1406.3057 [astro-ph.CO]
Sean M. Carroll, In What Sense Is the Early Universe Fine -Tuned?, arXiv:1406.3057 [astro-ph.CO]
-
[60]
Gibbons, Neil Turok, The Measure Problem in Cosmol ogy, Phys.Rev.D 77 (2008) 063516, arXiv:hep-th/0609095 [hep-th]
G.W. Gibbons, Neil Turok, The Measure Problem in Cosmol ogy, Phys.Rev.D 77 (2008) 063516, arXiv:hep-th/0609095 [hep-th]
2008 arXiv
-
[61]
Fa Peng Huang, The First Particles, arXiv:2501.15543 [ hep-ph]
-
[62]
George Ellis, Jean-Philippe Uzan, Causal structures i n cosmology, Comptes Rendus Physique 16 (2015) 928, arXiv:1612.01084 [gr-qc]
2015 arXiv
-
[63]
S Kobayashi and K Nomizu, Foundations of Differential Geometry I , Interscience, New York (1963)
1963
-
[64]
Wald, General Relativity, Chicago Universit y Press, Chicago, 1984
Robert M. Wald, General Relativity, Chicago Universit y Press, Chicago, 1984
1984
-
[65]
Tsagas, John D
Klaountia Pasmatsiou, Christos G. Tsagas, John D. Barr ow, Kinematics of Einstein- Cartan universes, Phys. Rev. D 95, 104007 (2017), arXiv:161 1.07878 [gr-qc]
2017
-
[66]
Sergio Bravo Medina, Marek Nowakowski, Davide Batic, E instein-Cartan Cosmolo- gies, Annals of Physics 400 (2019) 64-108, arXiv:1812.0458 9 [gr-qc]
2019
-
[67]
Daniele Bertacca, Raul Jimenez, Sabino Matarrese, Ang elo Ricciardone, Inflation without an Inflaton, arXiv:2412.14265 [astro-ph.CO] 36
-
[68]
62 (2024) 1, 287-331, arXiv:23 11.13305 [astro-ph.CO]
Licia Verde, Nils Schöneberg, Héctor Gil-Marín, A Tale of Many H 0, Ann.Rev.Astron.Astrophys. 62 (2024) 1, 287-331, arXiv:23 11.13305 [astro-ph.CO]
2024
-
[69]
Saridakis, Interpreting cosmological tensions from the effective field theory of torsional gravity, Phys
Sheng-Feng Yan, Pierre Zhang, Jie-Wen Chen, Xin-Zhe Zh ang, Yi-Fu Cai, Emmanuel N. Saridakis, Interpreting cosmological tensions from the effective field theory of torsional gravity, Phys. Rev. D 101, 121301 (2020), arXiv:1 909.06388 [astro-ph.CO]
2020
-
[70]
Thiago Pereira, Cyril Pitrou, Isotropization of the un iverse during inflation, Comptes Rendus Physique 16 (2015) 1027-1037, arXiv:1509.09166 [as tro-ph.CO]
2015 arXiv
-
[71]
Goldwirth, Conditions for inflation in an initially inho- mogeneous universe, Phys.Rev.D 51 (1995) 1563-1568, arXiv :gr-qc/9409056 [gr-qc]
Nathalie Deruelle, Dalia S. Goldwirth, Conditions for inflation in an initially inho- mogeneous universe, Phys.Rev.D 51 (1995) 1563-1568, arXiv :gr-qc/9409056 [gr-qc]
1995 arXiv
-
[72]
Tanmay Vachaspati, Mark Trodden, Causality and cosmic inflation, Phys.Rev.D 61 (1999) 023502, arXiv:gr-qc/9811037 [gr-qc]
1999 arXiv
-
[73]
Saridakis, Dynamics of the anis otropic Kantowsky-Sachs geometries in Rn gravity, Class.Quant.Grav
Genly Leon, Emmanuel N. Saridakis, Dynamics of the anis otropic Kantowsky-Sachs geometries in Rn gravity, Class.Quant.Grav. 28 (2011) 065008, arXiv:1007. 3956 [gr- qc]
2011
-
[74]
41 (2024) 7, 077002 , arXiv:2311.06881 [gr-qc]
George F R Ellis, David Garfinkle, The Synge G-Method: co smology, wormholes, firewalls, geometry, Class.Quant.Grav. 41 (2024) 7, 077002 , arXiv:2311.06881 [gr-qc]
2024 arXiv
-
[75]
Ellis, Jeff Murugan, Holonomy in the Schwarzschild- Droste geometry, Class.Quant.Grav
Tony Rothman, George F.R. Ellis, Jeff Murugan, Holonomy in the Schwarzschild- Droste geometry, Class.Quant.Grav. 18 (2001) 1217-1234, a rXiv:gr-qc/0008070 [gr- qc]
2001 arXiv
-
[76]
Pirani, Republication of: On the physical signi ficance of the Riemann tensor
F.A.E. Pirani, Republication of: On the physical signi ficance of the Riemann tensor. Gen Relativ Gravit 41, 1215-1232 (2009) 37
2009
Reviewed August 11, 2026 · model on record in the stance chip above.
Discussion (0). Continue with ORCID to comment.