| Homepage |
| Curriculum vitae |
| Publications |
| Teaching (czech) |
| Contact |
Open problems
During my research I found a couple of problems which I believe are interesting. I post some of them here. Some of the problems we are/were working on on the DiMaS seminar.
Please, let me know if you have results, partial results or some other information on any of the problems.
Multipartite graph decompositions
Find a decomposition of Kk[mK1] into Cr if r does not divide the number of edges of Kk nor does r divide m (and necessary condition that m divides 1/2*k(k-1)m2 holds).
Vertex magic total labelings
Find a VMT labeling of C2m × C2n.
Find a VMT labeling of any 2-regular graph (other than kCn).
Find a VMT labeling of any 3-regular graph (other than described by D. McQuillan: every 3-regular graph G with a perfect matching F, such that G-F consists of two 2-regular graphs, each on n vertices).
Are there other general methods besides decompositions and Kotzig arrays for finding magic-type labelings of large graphs using magic-type labelings of small graphs?
Find an infinite class of graphs with an isolate which allows a VMT labeling.
Find a VMT labeling of the Möbious ladder.
Find a VMT labeling with consecutive vertex labels for any 3-regular graph (or at least 3-regular graphs with perfect matching). The condition |G|=0(mod4) must hold.
For more information see www1.cs.columbia.edu/~sanders/graphtheory/people/, homel.vsb.cz/~kov16/publications/ms_thesis.php, and homel.vsb.cz/~kov16/publications/phd_thesis.php.
Vertex antimagic total labelings of cycles
Find a general construction of antimagic labelings with difference 4 and 5.
For more information see www.tuke.sk/baca/publications.htm or homel.vsb.cz/~kov16/publications/ms_thesis.php.
Vertex antimagic total labelings of regular graphs
Find a VAMT labeling of nK2 for n even (if exists).
Or at least find a VAMT labeling of any 3-regular graph.
For more information see homel.vsb.cz/~kov16/publications/graphs2005.php and homel.vsb.cz/~kov16/publications/iwogl2005.php.
Antimagic squares
Give a simple argument, that there is no antimagic square of order 3.
For definitions see mathworld.wolfram.com/AntimagicSquare.html or io.uwinnipeg.ca/~vlinek/jcormie/, for more information see www.geocities.com/~harveyh/anti_ms.htm and for more links see mathworld.wolfram.com/MagicSquare.html or www.geocities.com/~harveyh/.
 |
Petr<dot>Kovar<at>vsb<dot>cz phone ++420 / 597 325 972 |
Last update: 29.12.2011 |