Billiards in convex bodies with acute angles Akopyan, Arseniy ; https://orcid.org/0000-0002-2548-617X Balitskiy, Alexey In this paper we investigate the existence of closed billiard trajectories in not necessarily smooth convex bodies. In particular, we show that if a body K ⊂ Rd has the property that the tangent cone of every non-smooth point q ∉ ∂K is acute (in a certain sense), then there is a closed billiard trajectory in K. Springer 2016 info:eu-repo/semantics/article doc-type:article text http://purl.org/coar/resource_type/c_2df8fbb1 https://research-explorer.ista.ac.at/record/1330 Akopyan A, Balitskiy A. Billiards in convex bodies with acute angles. <i>Israel Journal of Mathematics</i>. 2016;216(2):833-845. doi:<a href="https://doi.org/10.1007/s11856-016-1429-z">10.1007/s11856-016-1429-z</a> eng info:eu-repo/semantics/altIdentifier/doi/10.1007/s11856-016-1429-z info:eu-repo/semantics/altIdentifier/wos/000386356400012 info:eu-repo/semantics/altIdentifier/arxiv/1506.06014 info:eu-repo/semantics/openAccess