Caro et al. proved that every tree of order n contains an induced subgraph of order at least rn/2] with all degrees odd, and conjectured a better bound. In this note we prove that every tree of order n contains an induced subgraph of order at least 2L(n + 1)/3 .] with all degrees odd; this bound is
โฆ LIBER โฆ
All trees contain a large induced subgraph having all degrees 1 (mod k)
โ Scribed by David M. Berman; A.J. Radcliffe; A.D. Scott; Hong Wang; Larry Wargo
- Publisher
- Elsevier Science
- Year
- 1997
- Tongue
- English
- Weight
- 260 KB
- Volume
- 175
- Category
- Article
- ISSN
- 0012-365X
No coin nor oath required. For personal study only.
โฆ Synopsis
We prove that, for integers n/>2 and k~>2, every tree with n vertices contains an induced subgraph of order at least 2/(n + 2k -3)/(2k -1)j with all degrees congruent to 1 modulo k. This extends a result of Radcliffe and Scott, and answers a question of Caro et al.