• spectral graph theory, a Ramanujan graph is a regular graph whose spectral gap is almost as large as possible (see extremal graph theory). Such graphs are...
    20 KB (2,792 words) - 01:39, 7 May 2025
  • Thumbnail for Srinivasa Ramanujan
    mathematicians List of Indian mathematicians Ramanujan graph Ramanujan summation Ramanujan's constant Ramanujan's ternary quadratic form Rank of a partition...
    106 KB (11,713 words) - 19:08, 6 July 2025
  • constructions to produce Ramanujan graphs with a fixed vertex size and degree of regularity. The results show the Ramanujan graphs exist for every vertex...
    41 KB (5,391 words) - 22:16, 19 June 2025
  • Theory, Group Theory and Ramanujan Graphs is a book in mathematics whose goal is to make the construction of Ramanujan graphs accessible to undergraduate-level...
    8 KB (1,043 words) - 01:17, 12 July 2025
  • to be Ramanujan graphs, graphs with optimal expansion properties for their degree. The proof is based on Pierre Deligne's proof of the Ramanujan–Petersson...
    6 KB (655 words) - 03:48, 30 November 2024
  • In mathematics, the Ramanujan conjecture, due to Srinivasa Ramanujan (1916, p. 176), states that Ramanujan's tau function given by the Fourier coefficients...
    20 KB (2,499 words) - 01:44, 28 May 2025
  • arrows. radius The radius of a graph is the minimum eccentricity of any vertex. Ramanujan A Ramanujan graph is a graph whose spectral expansion is as...
    109 KB (16,011 words) - 12:09, 30 June 2025
  • finite fields. These remarkable Ramanujan graphs also have large expansion coefficient. The odd girth and even girth of a graph are the lengths of a shortest...
    7 KB (903 words) - 07:28, 19 December 2024
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    edges. It is a strongly regular graph, a distance-transitive graph, and a Ramanujan graph. Although its construction is folklore, it was named after Andries...
    6 KB (714 words) - 00:30, 19 August 2023
  • Ihara zeta function (category Algebraic graph theory)
    reinterpreted graph-theoretically. It was Toshikazu Sunada who put this suggestion into practice in 1985. As observed by Sunada, a regular graph is a Ramanujan graph...
    6 KB (782 words) - 03:32, 9 January 2025
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    the two-by-two p-adic special linear group. A regular finite graph is a Ramanujan graph, a mathematical model of efficient communication networks, if...
    127 KB (16,781 words) - 22:34, 19 June 2025
  • 2{\sqrt {d-1}}-o(1)} . This bound is tight in the Ramanujan graphs. Suppose two directed or undirected graphs G1 and G2 with adjacency matrices A1 and A2 are...
    20 KB (2,453 words) - 03:31, 18 May 2025
  • Alon–Boppana bound (category Algebraic graph theory)
    eigenvector. The graphs that come close to meeting this bound are Ramanujan graphs, which are examples of the best possible expander graphs. Its discoverers...
    9 KB (1,908 words) - 09:11, 4 April 2025
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    Miguel A (2006-08-07). "Optimal network topologies: expanders, cages, Ramanujan graphs, entangled networks and all that". Journal of Statistical Mechanics:...
    7 KB (873 words) - 09:36, 27 May 2025
  • Thumbnail for Nikhil Srivastava
    solving long-standing questions on the Kadison-Singer problem and on Ramanujan graphs.[1] In 2022 The Ciprian Foias Prize in Operator Theory was awarded...
    4 KB (335 words) - 11:20, 5 January 2024
  • Thumbnail for Peter Sarnak
    (with A. Lubotzky and R. Phillips) applied results in number theory to Ramanujan graphs, with connections to combinatorics and computer science. Sarnak has...
    12 KB (965 words) - 04:22, 26 May 2025
  • machine Ramanujan–Nagell equation Ramanujan–Peterssen conjecture Ramanujan–Soldner constant Ramanujan summation Ramanujan theta function Ramanujan graph Ramanujan's...
    3 KB (259 words) - 11:35, 16 December 2024
  • Thumbnail for Cage (graph theory)
    (1988), "Ramanujan graphs", Combinatorica, 8 (3): 261–277, doi:10.1007/BF02126799, MR 0963118. Tutte, W. T. (1947), "A family of cubical graphs", Proc....
    9 KB (897 words) - 03:35, 18 May 2025
  • Thiruvenkatachari Parthasarathy. Ramanujan theta function, Ramanujan prime, Ramanujan summation, Ramanujan graph and Ramanujan's sum – Discovered by the Indian...
    213 KB (23,747 words) - 10:38, 15 July 2025
  • Thumbnail for Partition function (number theory)
    Srinivasa Ramanujan first discovered that the partition function has nontrivial patterns in modular arithmetic, now known as Ramanujan's congruences...
    27 KB (4,364 words) - 02:25, 23 June 2025
  • Thumbnail for Arithmetic group
    can be used to construct expander graphs (Margulis), or even Ramanujan graphs (Lubotzky-Phillips-Sarnak). Such graphs are known to exist in abundance by...
    22 KB (3,301 words) - 00:30, 20 June 2025
  • combinatorics, algebraic, differential, discrete and Euclidean geometries, graph theory, group theory, model theory, number theory, set theory, Ramsey theory...
    195 KB (20,033 words) - 13:09, 12 July 2025
  • Thumbnail for Grigory Margulis
    gave the first construction of expander graphs, which was later generalized in the theory of Ramanujan graphs. In 1986, Margulis gave a complete resolution...
    13 KB (1,366 words) - 17:50, 13 March 2025
  • A.; Srivastava, Nikhil (2015), "Interlacing families I: Bipartite Ramanujan graphs of all degrees", Annals of Mathematics, 182 (1): 307–325, arXiv:1304...
    9 KB (594 words) - 00:46, 18 March 2025
  • In graph theory, a graph is said to be a pseudorandom graph if it obeys certain properties that random graphs obey with high probability. There is no concrete...
    16 KB (2,768 words) - 09:21, 4 July 2025
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    of Integer Quaternions". Elementary Number Theory, Group Theory and Ramanujan Graphs. London Mathematical Society Student Texts. Vol. 55. Cambridge University...
    126 KB (15,335 words) - 08:49, 12 July 2025
  • theory to construct efficient communication networks called Ramanujan graphs and Ramanujan complexes. Li did her undergraduate studies at National Taiwan...
    6 KB (335 words) - 21:44, 29 April 2025
  • 2021 for their solution to long-standing conjectures in the study of Ramanujan graphs. Marcus grew up in Marietta, Georgia and was a boarding student at...
    7 KB (587 words) - 00:26, 1 May 2025
  • Ramanujan Institute for Advanced Study in Mathematics (RIASM) is the Department of Mathematics of University of Madras. This name was adopted in 1967...
    8 KB (973 words) - 12:27, 16 July 2024
  • Thumbnail for Odd cycle transversal
    Odd cycle transversal (category Graph theory objects)
    In graph theory, an odd cycle transversal of an undirected graph is a set of vertices of the graph that has a nonempty intersection with every odd cycle...
    6 KB (663 words) - 17:39, 26 March 2025