On the stability of the universal quotient bundle restricted to congruences of low degree of $𝔾\left(\mathbf{1},\mathbf{3}\right)$
Annali della Scuola Normale Superiore di Pisa - Classe di Scienze, Serie 5, Volume 9 (2010) no. 3, p. 503-522

We study the semistability of ${Q|}_{S}$, the universal quotient bundle on $𝔾$(1,3) restricted to any smooth surface $S$ (called congruence). Specifically, we deduce geometric conditions for a congruence $S$, depending on the slope of a saturated linear subsheaf of ${Q|}_{S}$. Moreover, we check that the Dolgachev-Reider Conjecture (i.e. the semistability of ${Q|}_{S}$ for nondegenerate congruences $S$) is true for all the congruences of degree less than or equal to 10. Also, when the degree of a congruence $S$ is less than or equal to 9, we compute the highest slope reached by the linear subsheaves of ${Q|}_{S}$.

Classification:  14J60,  14M07,  14M15
@article{ASNSP_2010_5_9_3_503_0,
author = {Arrondo, Enrique and Cobo, Sof\'\i a},
title = {On the stability of the universal quotient bundle restricted to congruences of low degree of $\mathbb{G}{\bf (1,3)}$},
journal = {Annali della Scuola Normale Superiore di Pisa - Classe di Scienze},
publisher = {Scuola Normale Superiore, Pisa},
volume = {Ser. 5, 9},
number = {3},
year = {2010},
pages = {503-522},
zbl = {1202.14038},
mrnumber = {2722653},
language = {en},
url = {http://www.numdam.org/item/ASNSP_2010_5_9_3_503_0}
}

Arrondo, Enrique; Cobo, Sofía. On the stability of the universal quotient bundle restricted to congruences of low degree of $\mathbb{G}{\bf (1,3)}$. Annali della Scuola Normale Superiore di Pisa - Classe di Scienze, Serie 5, Volume 9 (2010) no. 3, pp. 503-522. http://www.numdam.org/item/ASNSP_2010_5_9_3_503_0/

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