12 / 2017: 'Lagrangian theory of structure formation in relativistic cosmology. IV. Lagrangian approach to gravitational waves'
F. Al Roumi, T. Buchert and A. Wiegand,
Phys. Rev. D 96, 123538. (16 pages)

01 / 2018: 'On Backreaction in Newtonian cosmology'
T. Buchert,
Mon. Not. Roy. Astron. Soc. Letters 473, L46-L49. (4 pages)

06 / 2018: 'Is Dark Energy Simulated by Structure Formation in the Universe?'
T. Buchert,
Proceedings of Science EDSU2018 Conf-Id 335, 038. (8 pages)

08 / 2018: 'Lagrangian theory of structure formation in relativistic cosmology. V. Irrotational fluids'
Y.-Z. Li, P. Mourier, T. Buchert and D.L. Wiltshire,
Phys. Rev. D 98, 043507. (28 pages)

08 / 2018: 'Globally static and stationary inhomogeneous cosmologies'
F. Sartini,
Internship Report Master 1, May-July 2018, ENS Lyon (France). (23 pages)

08 / 2018: 'Averaged Inhomogeneous Cosmology: Fit to Supernovae without Dark Energy'
C. Desgrange,
Internship Report Licence 3, June-July 2018, UCB Lyon (France). (25 pages)

---

09/2018 - 08/2019 :

11 / 2018: 'Cosmological backreaction and its dependence on spacetime foliation'
T. Buchert, P. Mourier and X. Roy,
Class. Quant. Grav. 35, 24LT02. (9 pages)

11 / 2018: 'Space Is the Place - How to master spatial average properties of the Universe?'
T. Buchert, P. Mourier and X. Roy,
Class. Quant. Grav. Plus Invited Insight Comment, November 28 (2018).

03 / 2019: '4MOST Consortium Survey 8: Cosmology Redshift Survey (CRS)'
J. Richard, J.-P. Kneib, C. Blake, A. Raichoor, J. Comparat, T. Shanks, J. Sorce, M. Sahlén, C. Howlett, E. Tempel, R. McMahon, M. Bilicki, B. Roukema, J. Loveday, D. Pryer, T. Buchert and C. Zhao (for the CRS team),
The Messenger 175, 50. (4 pages)

04 / 2019: 'On the covariance of scalar averaging and backreaction in relativistic inhomogeneous cosmology'
A. Heinesen, P. Mourier and T. Buchert,
Class. Quant. Grav. 36, 075001. (20 pages)

05 / 2019: 'Topology and Geometry of Gaussian random fields I: on Betti Numbers, Euler characteristic and Minkowski functionals'
P. Pranav, R. van de Weygaert, G. Vegter, B.J.T. Jones, R.J. Adler, J. Feldbrugge, C. Park, T. Buchert and M. Kerber,
Mon. Not. Roy. Astron. Soc. 485, 4167. (42 pages)

06 / 2019: 'The environment-dependence of the growth of the most massive objects in the Universe'
K. Bolejko and J.J. Ostrowski,
Phys. Rev. D 99, 124036. (8 pages)

07 / 2019: 'Unexpected Topology of the Temperature Fluctuations in the Cosmic Microwave Background'
P. Pranav, R.J. Adler, T. Buchert, H. Edelsbrunner, B.J.T. Jones, A. Schwartzman, H. Wagner and R. van de Weygaert,
Astron. Astrophys. 627, A163. (30 pages)

07 / 2019: 'Dynamical spatial curvature as a fit to type Ia supernovae'
C. Desgrange, A. Heinesen and T. Buchert,
Int. J. Mod. Phys. D 28, 1950143. (23 pages)

08 / 2019: 'Dark Matter from Backreaction? Collapse models on galaxy cluster scales'
Q. Vigneron and T. Buchert,
Class. Quant. Grav. 36, 175006. (31 pages)

08 / 2019: 'Averaging in Newtonian Inhomogeneous Cosmology'
R. Faure,
Internship Report Master 1, May-July 2019, UCB Lyon (France). (29 pages)

08 / 2019: 'Characterization of an anomaly of the CMB in the standard LCDM model: Alignment of low-order multipoles with the ecliptic plane (in French)'
C. Richard,
Internship Report Licence 3, June-July 2019, UCB Lyon (France). (20 pages)

08 / 2019: 'The Inhomogeneous Radiation Cosmos'
S. Hirve,
Internship Report Licence 3, May-July 2019, ENS Lyon-IISER Pune (France-India). (5 pages)

---

09/2019 - 08/2020 :

09 / 2019: 'Inhomogeneous Relativistic Cosmology: nonperturbative models and spatial averaging of the Einstein equations'
P. Mourier,
PhD Thesis, HAL open archive 2019LYSE1116, tel-02299373 (198 pages)

09 / 2019: 'Stochastic Homology of Gaussian vs. non-Gaussian random fields: graphs towards Betti numbers and Persistence Diagrams'
J. Feldbrugge, M. van Engelen, R. van de Weygaert, P. Pranav and G. Vegter,
J. Cosmol. Astropart. Phys. 09, 052. (44 pages)

12 / 2019: 'Editorial Note to: On the Newtonian Limit of Einstein's Theory of Gravitation (by Jürgen Ehlers)'
T. Buchert and T. Mädler,
Gen. Rel. Grav. 51, 162. (24 pages)

12 / 2019: 'A few numbers from the turnaround epoch of collapse'
J.J. Ostrowski,
Proceedings of The 6th Conference of the Polish Society on Relativity, to appear. (4 pages)

01 / 2020: 'Channels for streaming instability in dusty discs'
E. Jaupart and G. Laibe,
Mon. Not. Roy. Astron. Soc. 492, 4591. (8 pages)

01 / 2020: 'Reduced phase space optics for general relativity: Symplectic ray bundle transfer'
N. Uzun,
Class. Quant. Grav. 37, 045002. (35 pages)

03 / 2020: 'On average properties of inhomogeneous fluids in General Relativity III: General Fluid Cosmologies'
T. Buchert, P. Mourier and X. Roy,
Gen. Rel. Grav. 52, 27. (73 pages)

08 / 2020: 'Solving the curvature and Hubble parameter inconsistencies through structure formation-induced curvature'
A. Heinesen and T. Buchert,
Class. Quant. Grav. 37, 164001. (21 pages)

08 / 2020: 'Spherically symmetric solutions of General Relativity: topological constraints on average properties'
M. Chatelain,
Internship Report Master 1, May-July 2020, ENS Lyon (France). (30 pages)

08 / 2020: 'Towards a topological conservation law in averaged Newtonian cosmologies'
N. Cohen,
Internship Report Licence 3, June-July 2020, ENS Lyon-EPFL Lausanne (France-Switzerland). (20 pages)

---

09/2020 - 08/2021 :

10 / 2020: 'The Hawking energy on the past light cone in cosmology'
D. Stock,
Class. Quant. Grav. 37, 215005. (11 pages)

10 / 2020: 'Gauss-Bonnet-Chern approach to the averaged Universe'
L. Brunswic and T. Buchert,
Class. Quant. Grav. 37, 215022. (41 pages)

10 / 2020: 'Cosmological homogeneity scale estimates are dressed'
A. Heinesen,
J. Cosmol. Astropart. Phys. 10, 052. (19 pages)

12 / 2020: '1+3 Formulation of Newton's equations'
Q. Vigneron,
Phys. Rev. D 102, 124005. (26 pages)

01 / 2021: 'Lagrangian theory of structure formation in relativistic cosmology. VI. Comparison with Szekeres exact solutions'
I. Delgado Gaspar and T. Buchert,
Phys. Rev. D 103, 023513. (29 pages)

01 / 2021: 'Multipole decomposition of redshift drift: Model-independent mapping of the expansion history of the Universe'
A. Heinesen,
Phys. Rev. D 103, 023537. (5 pages)

03 / 2021: 'The 1+3-Newton-Cartan system and Newton-Cartan cosmology'
Q. Vigneron,
Phys. Rev. D 103, 064064. (11 pages)

04 / 2021: 'A comparison theorem for cosmological lightcones'
M. Carfora and F. Familiari,
Lett. Math. Phys.111, 53. (19 pages)

04 / 2021: 'Redshift drift as a model-independent probe of dark energy'
A. Heinesen,
Phys. Rev. D 103, L081302. (7 pages)

05 / 2021: 'Multipole decomposition of the general luminosity distance Hubble law -- a new framework for observational cosmology'
A. Heinesen,
J. Cosmol. Astropart. Phys. 05, 008. (22 pages)

06 / 2021: 'Book Review: Computational topology for Biomedical Images and Data: Theory and applications'
P. Pranav,
IEEE Signal Processing Magazine 38, 130. (2 pages)

07 / 2021: 'Luminosity distance and anisotropic sky-sampling at low redshifts: a numerical relativity study'
H.J. Macpherson and A. Heinesen,
Phys. Rev. D 104, 023525. (20 pages)

08 / 2021: 'Backreaction and Virialization: Volume partitioning of inhomogeneous Newtonian cosmologies'
A. Bovon,
Internship Report Master 2, April-July 2021, ENS Lyon (France). (31 pages)

08 / 2021: 'Inhomogeneities and Anisotropies in the Universe analyzed with Supernovae of Type Ia'
A. Borderies,
Internship Report Master 1, May-July 2021, UCB Lyon (France). (22 pages)

---

09/2021 - 08/2022 :

09 / 2021: 'Influence of the topology in inhomogeneous cosmology through non-Euclidean extensions of Newton's theory and relativistic numerical schemes'
Q. Vigneron,
PhD Thesis, HAL open archive 2021LYSE1117, tel-03481716 (188 pages)

10 / 2021: 'Cauchy-compact flat spacetimes with extreme BTZ'
L. Brunswic,
Geometriae Dedicata 214, 571. (38 pages)

10 / 2021: 'Persistent homology of the cosmic web. I: Hierarchical topology in ΛCDM cosmologies'
G. Wilding, K. Nevenzeel, R. van de Weygaert, G. Vegter, P. Pranav, B.J.T. Jones, K. Efstathiou and J. Feldbrugge,
Mon. Not. Roy. Astron. Soc. 507, 2968. (23 pages)

10 / 2021: 'The variance of the CMB temperature gradient: a new signature of a multiply connected Universe'
R. Aurich, T. Buchert, M.J. France and F. Steiner,
Class. Quant. Grav. 38, 225005. (31 pages)

12 / 2021: 'Redshift drift cosmography for model-independent cosmological inference'
A. Heinesen,
Phys. Rev. D 104, 123527. (10 pages)

02 / 2022: 'Is backreaction in cosmology a relativistic effect? On the need for an extension of Newton's theory to non-Euclidean topologies'
Q. Vigneron,
Phys. Rev. D 105, 043524. (9 pages)

03 / 2022: 'Anomalies in the topology of the temperature fluctuations in the cosmic microwave background: An analysis of the NPIPE and FFP10 data releases'
P. Pranav,
Astron. Astrophys. 659, A115. (21 pages)

03 / 2022: 'A prediction for anisotropies in the nearby Hubble flow'
A. Heinesen and H.J. Macpherson,
J. Cosmol. Astropart. Phys. 03, 057. (22 pages)

04 / 2022: 'Minkowski Functionals of SDSS-III BOSS: Hints of possible anisotropy in the density field?'
S. Appleby, C. Park, P. Pranav, S.E. Hong, H.S. Hwang, J. Kim and T. Buchert,
Astrophys. J. 928, 108. (23 pages)

06 / 2022: 'Cosmology Intertwined: A review of the particle physics, astrophysics, and cosmology associated with the cosmological tensions and anomalies'
E. Abdalla et al., SNOWMASS collaboration
JHEAp 34, 49. (224 pages)

07 / 2022: 'Hydrodynamic interpretation of generic squeezed coherent states: A kinetic theory'
N. Uzun,
Ann. Phys. 442, 168900. (33 pages)

08 / 2022: 'Redshift drift in a universe with structure I: Lemaitre-Tolman-Bondi structures with arbitrary angle of entry of light'
S.M. Koksbang and A. Heinesen,
Phys. Rev. D 106, 043501. (12 pages)

08 / 2022: 'Non-perturbative collapse models for collisionless self-gravitating flows'
N. Fardeau,
Internship Report Master 1, May-July 2022, UCB Lyon (France). (30 pages)

08 / 2022: 'Inhomogeneous Cosmology in Spherical Space'
A. Courty,
Internship Report Master 1, May-July 2022, ENS Lyon (France). (30 pages)

---

09/2022 - 08/2023 :

11 / 2022: 'Cosmic Microwave Background properties in a Universe with simply or multiply connected topology'
M.J. France,
PhD Thesis, HAL open archive 2022LYSE1017, tel-03908491 (144 pages)

11 / 2022: 'On general-relativistic Lagrangian perturbation theory and its non-perturbative generalization'
T. Buchert, I. Delgado Gaspar and J.J. Ostrowski
Universe 8, 583. (25 pages)

01 / 2023: 'The averaging problem on the past null cone in inhomogeneous dust cosmologies'
T. Buchert, H.v. Elst and A. Heinesen,
Gen. Rel. Grav. 55, 7. (40 pages)

01 / 2023: 'Beyond relativistic Lagrangian perturbation theory. I. An exact-solution controlled model for structure formation'
I. Delgado Gaspar, T. Buchert and J.J. Ostrowski
Phys. Rev. D 107, 024018. (22 pages)

02 / 2023: 'Einstein Constraints and Ricci Flow---A Geometrical Averaging of Initial Data Sets'
M. Carfora and A. Marzuoli,
Mathematical Physics Studies ISSN 0921-3767, Springer, Singapore. (172 pages)

03 / 2023: 'The quadrupole in the local Hubble parameter: first constraints using Type Ia supernova data and forecasts for future surveys'
S. Dhawan, A. Borderies, H.J. Macpherson and A. Heinesen,
Mon. Not. Roy. Astron. Soc.519, 4841. (14 pages)

05 / 2023: 'Is the Observable Universe Consistent with the Cosmological Principle?'
P.K. Aluri, P. Cea, P. Chingangbam, M.-C. Chu, R.G. Clowes, D. Hutsemekers, J.P. Kochappan, A. Krasinski, A.M. Lopez, L. Liu, N.C.M. Martens, C.J.A.P. Martins, K. Migkas, E.O. Colgain, P. Pranav, L. Shamir, A.K. Singal, M.M. Sheikh-Jabbari, J. Wagner, S.-J. Wang, D.L. Wiltshire, Y. Shek, Y. Lu and W. Zhao,
Class. Quant. Grav. 40, 094001. (103 pages)

05 / 2023: 'Reconciling a decelerating Universe with cosmological observations'
A. Heinesen,
Phys. Rev. D 107, L101301. (6 pages)

07 / 2023: 'Gravitoelectromagnetism and Cosmology'
T. Boismard,
Internship Report Master 2, March-June 2023, UCB Lyon (France). (29 pages)

07 / 2023: 'Cosmologie inhomogène et contraintes topologiques'
F. de la Salle,
Internship Report Licence 3, June 2023, Paris-Saclay and UCB Lyon (France). (24 pages)

---

09/2023 - 08/2024 :

10 / 2023: 'Non-perturbative collapse models for collisionless self-gravitating flows'
N. Fardeau, T. Buchert, F. Al Roumi and F. Felegary,
Phys. Rev. D 108, 083502. (25 pages)

10 / 2023: 'Estimation of expected Euler characteristic curves of nonstationary smooth Gaussian random fields'
F.J.E. Telschow, A. Schwartzman, D. Cheng and P. Pranav,
Ann. Statist. 51, 2272. (25 pages)

11 / 2023: 'Direct correspondence between Newtonian gravitation and general relativity'
T. Buchert,
Phys. Rev. D 108, L101502. (6 pages)

11 / 2023: 'Bulk flows in the local Universe and the importance of relativistic effects'
A. Heinesen,
Phys. Rev. D 108, 103530. (9 pages)

01 / 2024: 'On elastic deformations of cylindrical bodies under the influence of the gravitational field'
H. Barzegar, P.T. Chruściel and F. Steininger,
Open Research Europe 4, 17329. (31 pages)

04 / 2024: 'Splitting the spacetime: A systematic analysis of foliation dependence in cosmic averaging'
P. Mourier and A. Heinesen,
J. Cosmol. Astropart. Phys. 04, 067. (46 pages)

08 / 2024: 'Exploring the rich geometrical information in cosmic drift signals with covariant cosmography'
A. Heinesen and M. Korzyński,
Phys. Rev. D 110, 043525. (14 pages)

06 / 2024: 'Characterization and modeling of the properties of the Alcubierre metric in an inertial approach'
A. Frackowiak,
Internship Report Master 1, May-June 2024, UCB Lyon (France). (12 pages)

---

09/2024 - 08/2025 :

03 / 2025: 'Homology reveals significant anisotropy in the cosmic microwave background'
P. Pranav and T. Buchert,
Astron. Astrophys. 695, A35. (18 pages)

07 / 2025: 'Novel realizations of warp drive spacetimes as solutions of general relativity'
A. Frackowiak,
Internship Report Master 2, March-June 2025, UCB Lyon (France). (32 pages)

08 / 2025: 'Beyond Homogeneity - spatial averaging, tilted fluids, and scalar evolution in D+1 General Relativity'
G. Léonard,
Internship Report Master 2, March-July 2025, Univ. Aix-Marseille (France). (47 pages)

---

09/2025 - 08/2026 :

09 / 2025: 'On restrictions of current warp drive spacetimes and immediate possibilities of improvement'
H. Barzegar and T. Buchert,
Universe 11, 293. (11 pages)

---

In progress :

xx / 2026: 'Novel realizations of warp drive spacetimes as solutions of General Relativity'
T. Buchert and A. Frackowiak,
Universe xx, to be submitted. (42 pages)

xx / 2026: 'Curvature and backreaction in the local Universe'
M. Galoppo, T. Buchert and P. Mourier,
XXX xx, to be submitted. (11 pages)

xx / 2026: 'Redshift dependence of postulated dark energy: an expected outcome of structure formation without dark energy'
T. Buchert and J.J. Ostrowski,
XXX xx, in preparation. (10 pages)

xx / 2026: 'Restricted motion in General Relativity'
H. Barzegar and T. Buchert,
Gen. Rel. Grav. xx, in preparation. (41 pages)

xx / 2026: 'Inhomogeneous cosmology in spherical space'
T. Buchert, P. Mourier and A. Courty,
XXX xx, in preparation. (37 pages)

xx / 2026: 'Homology of the Cosmic Microwave Background: Are finite universe models preferred over the infinite standard model?'
P. Pranav, T. Buchert and M.J. France,
XXX xx, in preparation. (25 pages)

xx / 2026: 'The Yamabe gap: Inhomogeneity measure and morphological driver of cosmic expansion'
L. Brunswic and T. Buchert,
Phys. Rev. Lett. XX, in preparation. (5 pages)

xx / 2026: 'Note on the relative Yamabe invariant of punctured manifolds of non-positive type'
L. Brunswic,
xxxxx XX, in preparation. (5 pages)

xx / 2026: 'Revisiting globally static and stationary cosmologies'
T. Buchert and F. Sartini,
Phil. Trans. Roy. Soc. London A XX, in preparation. (40 pages)

xx / 2026: 'Cosmological Backreaction and the Separate Universe Conjecture: I. Dynamical volume partitioning of Newtonian cosmologies'
T. Buchert, J.J. Ostrowski and A. Bovon,
Mon. Not. Roy. Astron. Soc. XX, in preparation. (13 pages)

xx / 2026: 'Morphological dynamics of spatial portions of the Universe'
T. Buchert,
Gen. Rel. Grav. XX, in preparation. (34 pages)

xx / 2026: 'Shape analysis in curved spacetime via Minkowski functionals'
N. Uzun and T. Buchert,
XXX XX, in preparation. (10 pages)

xx / 2026: 'Inhomogeneous Cosmology and the Dark Universe'
T. Buchert,
Universe XX, in preparation. (32 pages)

xx / 2026: 'Lagrangian theory of structure formation in relativistic cosmology. VII. Information entropies, backreaction, and the Penrose conjecture'
T. Buchert and P. Mourier,
Phys. Rev. D XX, in preparation. (30 pages)

---

Not resubmitted Preprints :

10 / 2020: 'On branched coverings of singular (G,X)-manifolds'
L. Brunswic,
Geometriae Dedicata XX, submitted. (35 pages)

12 / 2020: 'Alexandrov Theorem for 2+1 flat radiant spacetimes'
L. Brunswic,
Geom. Funct. Anal. XX, submitted. (56 pages)

09 / 2021: 'Topology and geometry of Gaussian random fields II: on critical points, excursion sets, and persistent homology'
P. Pranav,
Mon. Not. Roy. Astron. Soc. XX, submitted. (29 pages)

---

Last Update: January 1, 2026

Back to: AstroENS - ERC-ARThUs Group

---