RT Journal Article T1 The universal rank-(n − 1) bundle on G(1, n) restricted to subvarieties A1 Arrondo Esteban, Enrique AB The author has, in several articles, studied varieties in the Grassmannian G(k, n) of kplanes in projective n-space, that are projections from a variety in G(k,N). In the case k = 1 the varieties of dimension n−1 in G(1, n) that are projections from G(1,N) were studied by E. Arrondo and I. Sols [“On congruences of lines in the projective space”,M´em. Soc. Math. Fr., Nouv. S´er. 50 (1992; Zbl 0804.14016)] and solved for n = 3 by E. Arrondo [J. Algebr. Geom. 8, No. 1, 85-101 (1999; Zbl 0945.14030)]. In the paper under review the author studies the other extreme k = n−1, n−2. The case k = n−1 is solved completely, and in the case k = n−2 it is shown that if Y is a smooth variety of dimension s in G(1, n) whose dual Y in G(n − 2, n) is a non-trivial projection from G(n − 2, n + 1), then s = n − 1 and Y is completely classified. The methods are from classical projective geometry and based upon results by E. Rogora [Manuscr. Math. 82, No. 2, 207-226 (1994; Zbl 0812.14038)] and B. Segre. PB PPU SN 0010-0757 YR 1998 FD 1998 LK https://hdl.handle.net/20.500.14352/58419 UL https://hdl.handle.net/20.500.14352/58419 LA eng NO E. Arrondo, Projections of Grassmannians of lines and characterization of Veronese varieties, preprint (1997).E. Arrondo, M. Bertolini and C. Turrini, Classification of smooth congruences with a fundamental curve, pages 43-56 in Projective geometry with applications (ed. E. Ballico), Marcel Dekker, New York, 1994.E. Arrondo and I. Sols, On congruences of lines in the projective space, Soc. Math. France (M´em. 50), 1992.E. Rogora, Varieties with many lines, Manuscripta Math. 82 (1994),207-226. B. Segre, Sulle Vn aventi pi`u di ∞n−k Sk, I and II, Rend. dell’Acad. Naz. Lincei, vol. V (1948), 193-157 and 217-273. F. Severi, Intorno ai punti doppi impropri di una superficie generale dello spazio a quattro dimensioni, e a suoi punti tripli apparenti Rend. Circ. Mat. Palermo II, 15 (1901), 377–401. F.L Zak, Tangents and Secants of Algebraic Varieties, Transl. Math. Monographs AMS, vol. 127, Providence, RI, 1993 NO DGICYT DS Docta Complutense RD 5 may 2024