Alvarenga, F. G.Cruz Dombriz, Álvaro de laHoundjo, M. J. S.Rodrigues, M. E.Sáez Gómez, Diego2023-06-192023-06-192013-05-281550-799810.1103/PhysRevD.87.103526https://hdl.handle.net/20.500.14352/33810© 2013 American Physical Society. The authors would like to warmly thank A. L. Maroto for useful comments during the elaboration of the manuscript. A. d. l. C. D. acknowledges financial support from ACGC Research Fellowship University of Cape Town, MINECO (Spain) Projects No. FIS2011-23000 and No. FPA2011-27853-C02-01 and Consolider-Ingenio MULTIDARK CSD2009-00064. M. J. S. H. thanks CNPq-FAPES for financial support. M. E. R. thanks UFES for the hospitality during the elaboration of this work. D. S. G. acknowledges support from a postdoctoral contract from the University of the Basque Country (UPV/EHU) under the program Specialization of research staff, and support from the research Project No. FIS2010-15640, and also acknowledges financial support from URC (South Africa). M. E. R. wishes to thank PPGF of the UFPA for the hospitality during the development of this work and CNPq for partial financial support.In the context of f(R, T) theories of gravity, we study the evolution of scalar cosmological perturbations in the metric formalism. According to restrictions on the background evolution, a specific model within these theories is assumed in order to guarantee the standard continuity equation. Using a completely general procedure, we find the complete set of differential equations for the matter density perturbations. In the case of sub-Hubble modes, the density contrast evolution reduces to a second-order equation. We show that for well-motivated f(R, T) Lagrangians the quasistatic approximation yields to very different results from the ones derived in the frame of the concordance Lambda CDM model constraining severely the viability of such theories.engjournal articlehttp://dx.doi.org/10.1103/PhysRevD.87.103526http://journals.aps.org/open access53Dark energyExtended theoriesModelsReconstructionTermFísica (Física)22 Física