On the number of triangular embeddings of complete graphs and complete tripartite graphs

We prove that for every prime number $p$ and odd $m>1$, as $s\to\infty$, there are at least $w^{w^2\big(\frac 1{p^4m^2}-o(1)\big)}$ face 2-colourable triangular embeddings of $K_{w,w,w}$, where $w=m\cdot p^s$. For both orientable and nonorientable embeddings, this result implies that for infinitely many infinite families of $z$, there is a constant $c>0$ for which there are at least $z^{cz^2}$ nonisomorphic face 2-colourable triangular embeddings of $K_z$.

[1]  Martin Knor,et al.  Regular hamiltonian embeddings of Kn, n and regular triangular embeddings of Kn, n, n , 2008, Discret. Math..

[2]  Mike J. Grannell,et al.  BIEMBEDDINGS OF LATIN SQUARES AND HAMILTONIAN DECOMPOSITIONS , 2004, Glasgow Mathematical Journal.

[3]  Vladimir P. Korzhik,et al.  On the Number of Nonisomorphic Orientable Regular Embeddings of Complete Graphs , 2001, J. Comb. Theory, Ser. B.

[4]  Vladimir P. Korzhik,et al.  Exponentially many nonisomorphic orientable triangular embeddings of K12s+3 , 2009, Discret. Math..

[5]  Mike J. Grannell,et al.  Designs and topology , 2007 .

[6]  Vladimir P. Korzhik,et al.  Nonorientable biembeddings of Steiner triple systems , 2004, Discret. Math..

[7]  Vladimir P. Korzhik,et al.  Exponential Families of Non-isomorphic Non-triangular Orientable Genus Embeddings of Complete Graphs , 2002, J. Comb. Theory, Ser. B.

[8]  Mike J. Grannell,et al.  Exponential Families of Non-Isomorphic Triangulations of Complete Graphs , 2000, J. Comb. Theory, Ser. B.

[9]  Mike J. Grannell,et al.  On Biembeddings of Latin Squares , 2009, Electron. J. Comb..

[10]  G. Ringel Map Color Theorem , 1974 .

[11]  Mike J. Grannell,et al.  A lower bound for the number of orientable triangular embeddings of some complete graphs , 2010, J. Comb. Theory, Ser. B.

[12]  Mike J. Grannell,et al.  Biembeddings of Abelian groups , 2009 .

[13]  Jonathan L. Gross,et al.  Topological Graph Theory , 1987, Handbook of Graph Theory.

[14]  Vladimir P. Korzhik,et al.  Exponential families of nonisomorphic nonorientable genus embeddings of complete graphs , 2004, J. Comb. Theory, Ser. B.

[15]  Mike J. Grannell,et al.  Recursive constructions for triangulations , 2002 .

[16]  Mike J. Grannell,et al.  A lower bound for the number of triangular embeddings of some complete graphs and complete regular tripartite graphs , 2008, J. Comb. Theory, Ser. B.

[17]  Vladimir P. Korzhik Exponentially many nonisomorphic orientable triangular embeddings of K12s , 2008, Discret. Math..