{
  "abstract": "The persistent $H_0$ and $S_8$ tensions motivate the search for new dark-energy mechanisms capable of modifying the late-time expansion history while preserving the successful early-Universe predictions of $Λ$CDM scenario. Wald-Gauss-Bonnet (WGB) topological dark energy provides a physically motivated realization of this possibility, where the effective dark-energy sector emerges from cosmic horizon thermodynamics and the black-hole formation and merger history. We present the first early- and late-Universe analysis of WGB cosmology, implementing the model as an effective fluid in a modified \\texttt{CLASS} solver and constraining it against CMB data from \\textit{Planck}, ACT~DR6 and SPT-3G, DESI~DR2 BAO, and Pantheon+ supernovae. While late-time data alone are consistent with $Λ$CDM, the full dataset prefers a non-zero WGB contribution, $\\Cn=0.387^{+0.118}_{-0.072}$, corresponding to a $>3σ$ phantom-like deviation and an improved fit ($Δχ^2=-10.3$). The preferred solution raises $H_0$ from $68.5$ to $69.8~\\kmsmpc$, reducing the Hubble tension by $\\sim1σ$, at the cost of a mild increase in $S_8$. The reconstructed cosmological observables show that WGB leaves the primary CMB almost unchanged while enhancing lensing and small-scale clustering, revealing a characteristic $H_0$-$S_8$ trade-off. WGB dark energy therefore emerges as a physically motivated and observationally viable late-time mechanism for partially alleviating the Hubble tension without introducing new early-Universe physics.",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": null,
  "arxiv": "2607.26101",
  "author_total": 5,
  "authors": [
    {
      "name": "Stylianos A. Tsilioukas"
    },
    {
      "name": "Fotios K. Anagnostopoulos"
    },
    {
      "name": "Spyros Basilakos"
    },
    {
      "name": "Andronikos Paliathanasis"
    },
    {
      "name": "Emmanuel N. Saridakis"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/dpsp1z623szq7.bib",
  "cited_by": 0,
  "doi": "10.48550/arxiv.2607.26101",
  "fulltext_url": null,
  "id": "dpsp1z623szq7",
  "issns": [],
  "landing_url": "https://arxiv.org/abs/2607.26101",
  "language": null,
  "licence": "LicenseRef-arXiv-nonexclusive-1.0",
  "licence_label": "arXiv licence",
  "licence_source": "article",
  "licence_url": "http://arxiv.org/licenses/nonexclusive-distrib/1.0/",
  "metadata_licence": "CC0-1.0",
  "native_subjects": [
    [
      "arxiv",
      "astro-ph.CO"
    ],
    [
      "arxiv",
      "gr-qc"
    ],
    [
      "arxiv",
      "hep-th"
    ]
  ],
  "openalex": null,
  "pdf_url": "https://arxiv.org/pdf/2607.26101",
  "pmcid": null,
  "pmid": null,
  "published": "2026-10-30",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/dpsp1z623szq7.ris",
  "sources": [
    {
      "first_seen": "2026-11-02T12:21:15Z",
      "native_id": "2607.26101",
      "source": "arxiv",
      "url": "https://arxiv.org/abs/2607.26101"
    }
  ],
  "subjects": [
    {
      "field": "astronomy",
      "origin": "arxiv:astro-ph.CO",
      "subfield": "cosmology"
    },
    {
      "field": "physics",
      "origin": "arxiv:gr-qc",
      "subfield": "gravitation"
    },
    {
      "field": "physics",
      "origin": "arxiv:hep-th",
      "subfield": "high-energy"
    }
  ],
  "title": "Early- and late-time constraints on Wald-Gauss-Bonnet topological dark energy and implications for the $H_0$ and $S_8$ tensions",
  "title_text": "Early- and late-time constraints on Wald-Gauss-Bonnet topological dark energy and implications for the H_0 and S_8 tensions",
  "type": "preprint",
  "updated_at": "2026-11-04T15:20:50Z",
  "url": "https://research.draconitic.com/paper/dpsp1z623szq7",
  "venue": "arXiv",
  "versions": []
}