Instructions: 1. Give geometric interpretation and graphs where required. 2. Give your original work. 3. Use the recommended references and books. Abbott H.L., Lower bounds for some Ramsey numbers. Discr. Math. 2 (1972), 289-293. [393] Abeledo H. and G. Isaak, A characterization of graphs that ensure the existence of a stable matching. Math. Soc. Sci. 22 (1991), 93-96. [136] Aberth O., On the sum of graphs. Rev. Fr. Rech. Opér. 33 (1964), 353-358. [194] Acharya B.D. and M. Las Vergnas, Hypergraphs with cyclomatic number zero, triangulated graphs, and an inequality. J. Comb. Th. B 33 (1982), 52–56. [327] Ahuja R.K., T.L. Magnanti, and J.B. Orlin, Network Flows, Prentice Hall (1993). [97, 145, 176, 180, 185, 190] Aigner M., Combinatorial Theory. Springer-Verlag (1979). [355, 360, 373] Aigner M., Graphentheorie. Eine Entwicklung aus dem 4-Farben Problem. B.G. Teubner Verlagsgesellschaft (1984) (English transl. BCS Assoc., 1987). [258] Ajtai M., V. Chvátal, M.M. Newborn and E. Szemerédi, Crossing-free subgraphs. Theory and practice of combinatorics, Ann. Discr. Math. 12 (1982), 9-12. [264] Ajtai M., J. Komlós, and E. Szemerédi, A note on Ramsey numbers. J. Comb. Th (A) 29 (1980), 354-360. [51, 385] Ajtai M., J. Komlós, and E. Szemerédi, Sorting in clog parallel steps. Combi natorica 3 (1983), 1-19. [463] Akiyama J., H. Era, S.V. Gervacio and M. Watanabe, Path chromatic numbers of graphs. J. Graph Th. 13 (1989), 569-575. [271] Akiyama J, and F. Harary, A graph and its complement with specified properties, IV: Counting self-complementary blocks. J. Graph Th. 5 (1981), 103-107. [32] Albertson M.O. and E.H. Moore, Extending graph colorings. J. Comb. Th. (B) 77 (1999), 83-95. [204] Alekseev V.B. and V.S. Gončakov, The thickness of an arbitrary complete graph (Russian). Mat. Sb. (N.S.) 101(143) (1976), 212-230. [271] No AI, AI means Downvote. Problem 4: Geometric Representation Theory of Graphs on Complex Surfaces Explore the theory of representing graphs geometrically on complex surfaces, such as the complex projective plane CP². 1. Projective Plane Embeddings: •Prove that any planar graph that can be embedded in R² can also be embedded in CP² with a well-defined projective transformation. • Demonstrate how the projective transformation affects edge lengths, angles, and crossing numbers for a given geometric graph. 2. Complex Surfaces and Graph Homology: ⚫ Given a graph G embedded on CP², calculate its homology groups over the complex field C and relate this to the graph's properties, such as connectivity and genus. 3. Graph Automorphisms and Complex Structures: ⚫ Show that for any graph automorphism of a graph embedded on CP², there exists a corresponding complex conjugation symmetry in the embedding. Prove that this automorphism group is isomorphic to the fundamental group of the graph when embedded in CP²
Instructions: 1. Give geometric interpretation and graphs where required. 2. Give your original work. 3. Use the recommended references and books. Abbott H.L., Lower bounds for some Ramsey numbers. Discr. Math. 2 (1972), 289-293. [393] Abeledo H. and G. Isaak, A characterization of graphs that ensure the existence of a stable matching. Math. Soc. Sci. 22 (1991), 93-96. [136] Aberth O., On the sum of graphs. Rev. Fr. Rech. Opér. 33 (1964), 353-358. [194] Acharya B.D. and M. Las Vergnas, Hypergraphs with cyclomatic number zero, triangulated graphs, and an inequality. J. Comb. Th. B 33 (1982), 52–56. [327] Ahuja R.K., T.L. Magnanti, and J.B. Orlin, Network Flows, Prentice Hall (1993). [97, 145, 176, 180, 185, 190] Aigner M., Combinatorial Theory. Springer-Verlag (1979). [355, 360, 373] Aigner M., Graphentheorie. Eine Entwicklung aus dem 4-Farben Problem. B.G. Teubner Verlagsgesellschaft (1984) (English transl. BCS Assoc., 1987). [258] Ajtai M., V. Chvátal, M.M. Newborn and E. Szemerédi, Crossing-free subgraphs. Theory and practice of combinatorics, Ann. Discr. Math. 12 (1982), 9-12. [264] Ajtai M., J. Komlós, and E. Szemerédi, A note on Ramsey numbers. J. Comb. Th (A) 29 (1980), 354-360. [51, 385] Ajtai M., J. Komlós, and E. Szemerédi, Sorting in clog parallel steps. Combi natorica 3 (1983), 1-19. [463] Akiyama J., H. Era, S.V. Gervacio and M. Watanabe, Path chromatic numbers of graphs. J. Graph Th. 13 (1989), 569-575. [271] Akiyama J, and F. Harary, A graph and its complement with specified properties, IV: Counting self-complementary blocks. J. Graph Th. 5 (1981), 103-107. [32] Albertson M.O. and E.H. Moore, Extending graph colorings. J. Comb. Th. (B) 77 (1999), 83-95. [204] Alekseev V.B. and V.S. Gončakov, The thickness of an arbitrary complete graph (Russian). Mat. Sb. (N.S.) 101(143) (1976), 212-230. [271] No AI, AI means Downvote. Problem 4: Geometric Representation Theory of Graphs on Complex Surfaces Explore the theory of representing graphs geometrically on complex surfaces, such as the complex projective plane CP². 1. Projective Plane Embeddings: •Prove that any planar graph that can be embedded in R² can also be embedded in CP² with a well-defined projective transformation. • Demonstrate how the projective transformation affects edge lengths, angles, and crossing numbers for a given geometric graph. 2. Complex Surfaces and Graph Homology: ⚫ Given a graph G embedded on CP², calculate its homology groups over the complex field C and relate this to the graph's properties, such as connectivity and genus. 3. Graph Automorphisms and Complex Structures: ⚫ Show that for any graph automorphism of a graph embedded on CP², there exists a corresponding complex conjugation symmetry in the embedding. Prove that this automorphism group is isomorphic to the fundamental group of the graph when embedded in CP²