Constant angle surfaces in the Lorentzian warped product manifold – I × fE²

In this work, we study constant angle space-like and time-like surfaces in the 3-dimensional Lorentzian warped product manifold - I× fE² with the metric g~ = - d t²+ f²(t) (d x²+ d y²) , where I is an open interval, f is a strictly positive function on I, and E² is the Euclidean plane. We obtain a classification of all constant angle space-like and time-like surfaces in - I× fE². In this classification, we determine space-like and time-like surfaces with zero mean curvature, rotational surfaces, and surfaces with constant Gaussian curvature. Also, we obtain some results on constant angle space-like and time-like surfaces of the de Sitter space S13(1). Publisher's Version