Akademik Veri Yönetim Sistemi
PHYSICS OF THE DARK UNIVERSE, cilt.51, 2026 (SCI-Expanded, Scopus)
We study the late-time cosmological implications of Weyl-type f (Q, T) modified gravity in a spatially flat FLRW background. Working in Weyl geometry, where non-metricity is sourced by a gauge field w mu, we enforce the vanishing Weyl scalar condition R = 0 through a Lagrange multiplier, which yields modified field equations containing both a Proca-like vector contribution and a matter-geometry coupling via f(Q,T). By adopting the linear ansatz f (Q, T) = alpha Q +6,/i2 T + y and a homogeneous Weyl vector w mu =(r(t), 0, 0, 0)(so that Q = 6r2), we derive the generalized Friedmann equations and close the system under the approximation A similar or equal to ,2. The Weyl constraint admits the branch r = H, and consistency with the generalized Proca equation selects the massless effective mode m2eff = 0, fixing alpha and leaving (/i, y) as the relevant phenomenological parameters. For a dust sector (p = 0), the dynamics reduces to a Riccati-type equation that can be integrated analytically, leading to a closed-form expression for the Hubble function H(z) and well-defined viability conditions (notably /i not equal -2 and H2(z) >= 0). We then confront the model with current late-time data using an affine-invariant MCMC analysis with cosmic chronometer H(z) measurements, Pantheon+ SNe Ia, and DESI BAO. The combined dataset yields H0 = 67.86 +/- 0.37, /i = 0.27+0.11-0.13, and y =-1.8 x 104 +/- 1.0, with a goodness of fit comparable to Lambda CDM (x2red = 1.122 versus 1.115). The inferred H0 is consistent with Planck-inferred values but remains below local distance-ladder estimates. Finally, we reconstruct the cosmographic hierarchy {q, j, s, l} and find a standard deceleration-to-acceleration transition with an asymptotic de Sitter future, while higher-order kinematic quantities remain smooth and close to Lambda CDM within 1 sigma - 2 sigma bands. Hence, Weyl-type f(Q,T) gravity with a linear (Q, T) sector provides an analytically tractable late-time cosmology compatible with current observations, leaving room for small, testable departures in higher-order kinematics.