Research output: Contribution to journal › Article › peer-review
A note on panchromatic colorings. / Cherkashin, Danila.
In: Discrete Mathematics, Vol. 341, No. 3, 01.03.2018, p. 652-657.Research output: Contribution to journal › Article › peer-review
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TY - JOUR
T1 - A note on panchromatic colorings
AU - Cherkashin, Danila
PY - 2018/3/1
Y1 - 2018/3/1
N2 - This paper studies the quantity p(n,r), that is the minimal number of edges of an n-uniform hypergraph without panchromatic coloring (it means that every edge meets every color) in r colors. If [Formula presented] then all bounds have a type [Formula presented], where A1, A2 are some algebraic fractions. The main result is a new lower bound on p(n,r) when r is at least cn; we improve an upper bound on p(n,r) if n=o(r3∕2). Also we show that p(n,r) has upper and lower bounds depending only on n∕r when the ratio n∕r is small, which cannot be reached by the previous probabilistic machinery. Finally we construct an explicit example of a hypergraph without panchromatic coloring and with [Formula presented].
AB - This paper studies the quantity p(n,r), that is the minimal number of edges of an n-uniform hypergraph without panchromatic coloring (it means that every edge meets every color) in r colors. If [Formula presented] then all bounds have a type [Formula presented], where A1, A2 are some algebraic fractions. The main result is a new lower bound on p(n,r) when r is at least cn; we improve an upper bound on p(n,r) if n=o(r3∕2). Also we show that p(n,r) has upper and lower bounds depending only on n∕r when the ratio n∕r is small, which cannot be reached by the previous probabilistic machinery. Finally we construct an explicit example of a hypergraph without panchromatic coloring and with [Formula presented].
KW - Hypergraph colorings
KW - Panchromatic colorings
KW - EDGES
KW - UNIFORM HYPERGRAPHS
UR - http://www.scopus.com/inward/record.url?scp=85035814485&partnerID=8YFLogxK
U2 - 10.1016/j.disc.2017.10.030
DO - 10.1016/j.disc.2017.10.030
M3 - Article
AN - SCOPUS:85035814485
VL - 341
SP - 652
EP - 657
JO - Discrete Mathematics
JF - Discrete Mathematics
SN - 0012-365X
IS - 3
ER -
ID: 35109964