Theorems of Erdos-Ko-Rado type in polar spaces

نویسندگان

  • Valentina Pepe
  • Leo Storme
  • Frédéric Vanhove
چکیده

We consider Erdős-Ko-Rado sets of generators in classical finite polar spaces. These are sets of generators that all intersect non-trivially. We characterize the Erdős-Ko-Rado sets of generators of maximum size in all polar spaces, except for H(4n+ 1, q) with n ≥ 2.

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

منابع مشابه

Cross-Intersecting Erdős-Ko-Rado Sets in Finite Classical Polar Spaces

A cross-intersecting Erdős-Ko-Rado set of generators of a finite classical polar space is a pair (Y,Z) of sets of generators such that all y ∈ Y and z ∈ Z intersect in at least a point. We provide upper bounds on |Y | · |Z| and classify the crossintersecting Erdős-Ko-Rado sets of maximum size with respect to |Y | · |Z| for all polar spaces except some Hermitian polar spaces.

متن کامل

Intersection Properties of Subsets of Integers

Intersection properties of sets have been widely investigated by many authors. One type of theorems proved for them has the following form [9]. Let S be an n-element set and AI. ... , AN £ S, 1 £ [1, n]. Assume that IAi I1Ajl E 1 for 1,,;;;; i <j ,,;;;;N. How large can N be under this condition, depending on n and I? Thus, e.g., the de Bruijn-Erdos theorem [1] asserts that if IAi I1Ajl = 1 for ...

متن کامل

Erdos-Ko-Rado theorems for simplicial complexes

A recent framework for generalizing the Erdős-KoRado Theorem, due to Holroyd, Spencer, and Talbot, defines the Erdős-Ko-Rado property for a graph in terms of the graph’s independent sets. Since the family of all independent sets of a graph forms a simplicial complex, it is natural to further generalize the Erdős-Ko-Rado property to an arbitrary simplicial complex. An advantage of working in sim...

متن کامل

Towards a Katona Type Proof for the 2-intersecting Erdos-Ko-Rado Theorem

We study the possibility of the existence of a Katona type proof for the Erdős-Ko-Rado theorem for 2and 3-intersecting families of sets. An Erdős-Ko-Rado type theorem for 2-intersecting integer arithmetic progressions and a model theoretic argument show that such an approach works in the 2-intersecting case.

متن کامل

On the maximum size of Erdős-Ko-Rado sets in $$H(2d+1, q^2)$$

Erdős-Ko-Rado sets in finite classical polar spaces are sets of generators that intersect pairwise non-trivially. We improve the known upper bound for Erdős-Ko-Rado sets in H(2d + 1, q) for d > 2 and d even from approximately q +d to q 2+1.

متن کامل

ذخیره در منابع من


  با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

عنوان ژورنال:
  • J. Comb. Theory, Ser. A

دوره 118  شماره 

صفحات  -

تاریخ انتشار 2011