کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
9515332 1343446 2005 21 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
The Turán problem for projective geometries
موضوعات مرتبط
مهندسی و علوم پایه ریاضیات ریاضیات گسسته و ترکیبات
پیش نمایش صفحه اول مقاله
The Turán problem for projective geometries
چکیده انگلیسی
We consider the following Turán problem. How many edges can there be in a (q+1)-uniform hypergraph on n vertices that does not contain a copy of the projective geometry PGm(q)? The case q=m=2 (the Fano plane) was recently solved independently and simultaneously by Keevash and Sudakov (The Turán number of the Fano plane, Combinatorica, to appear) and Füredi and Simonovits (Triple systems not containing a Fano configuration, Combin. Probab. Comput., to appear). Here we obtain estimates for general q and m via the de Caen-Füredi method of links combined with the orbit-stabiliser theorem from elementary group theory. In particular, we improve the known upper and lower bounds in the case q=2, m=3.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Journal of Combinatorial Theory, Series A - Volume 111, Issue 2, August 2005, Pages 289-309
نویسندگان
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