Emission-Line Galaxies in the Era of Cosmological Surveys // Cosmological surveys in the next decade will contain multiwavelength information of billions of galaxies. The challenges ahead are distinguishing between different cosmological scenarios and/or gravity models and track accurately the build-up and formation history of galaxies. In this scenario, the role of galaxy formation is enhanced by the varied selection criteria of future surveys. Most future ground surveys, such as DESI, 4MOST, PFS and J-PAS, and space missions like Euclid and WFIRST are designed to target the so-called emission-line galaxies (ELGs). ELGs are abundant at high redshifts, and their distances can be precisely measured by identifying narrow strong emission lines in their spectra. However, there is still much to learn about their physical properties and the way they trace the matter distribution of the Universe. In this talk I will review recent progress characterizing the properties of ELGs with galaxy formation models. In particular, I will discuss galaxy formation effects that are crucial for modeling their clustering, especially in redshift space. Capturing these effects could thus result in tighter cosmological constraints and, ultimately, an optimal exploitation of future cosmological surveys.