机构:
Tohoku Univ, Grad Sch Informat Sci, Res Ctr Pure & Appl Math, Sendai, Miyagi 9808579, JapanTohoku Univ, Grad Sch Informat Sci, Res Ctr Pure & Appl Math, Sendai, Miyagi 9808579, Japan
Greaves, Gary
[1
]
Koolen, Jacobus H.
论文数: 0引用数: 0
h-index: 0
机构:
Univ Sci & Technol China, Sch Math Sci, Hefei 230026, Anhui, Peoples R ChinaTohoku Univ, Grad Sch Informat Sci, Res Ctr Pure & Appl Math, Sendai, Miyagi 9808579, Japan
Koolen, Jacobus H.
[2
]
Munemasa, Akihiro
论文数: 0引用数: 0
h-index: 0
机构:
Tohoku Univ, Grad Sch Informat Sci, Res Ctr Pure & Appl Math, Sendai, Miyagi 9808579, JapanTohoku Univ, Grad Sch Informat Sci, Res Ctr Pure & Appl Math, Sendai, Miyagi 9808579, Japan
Munemasa, Akihiro
[1
]
Szoellosi, Ferenc
论文数: 0引用数: 0
h-index: 0
机构:
Tohoku Univ, Grad Sch Informat Sci, Res Ctr Pure & Appl Math, Sendai, Miyagi 9808579, JapanTohoku Univ, Grad Sch Informat Sci, Res Ctr Pure & Appl Math, Sendai, Miyagi 9808579, Japan
Szoellosi, Ferenc
[1
]
机构:
[1] Tohoku Univ, Grad Sch Informat Sci, Res Ctr Pure & Appl Math, Sendai, Miyagi 9808579, Japan
[2] Univ Sci & Technol China, Sch Math Sci, Hefei 230026, Anhui, Peoples R China
We obtain several new results contributing to the theory of real equiangular line systems Among other things, we present a new general lower bound on the maximum number of equiangular lines in d dimensional Euclidean space; we describe the two-graphs on 12 vertices; and we investigate Seidel matrices with exactly three distinct eigenvalues. As a result, we improve on two long-standing upper bounds regarding the maximum number of equiangular lines in dimensions d = 14 and d = 16. Additionally, we prove the nonexistence of certain regular graphs with four eigenvalues, and correct some tables from the literature. (C) 2015 Elsevier Inc. All rights reserved.