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Graphs in which all maximal bipartite subgraphs have the same order [article]

Wayne Goddard, Kirsti Kuenzel, Eileen Melville
2019 arXiv   pre-print
Motivated by the concept of well-covered graphs, we define a graph to be well-bicovered if every vertex-maximal bipartite subgraph has the same order (which we call the bipartite number).  ...  We first give examples of them, compare them with well-covered graphs, and characterize those with small or large bipartite number.  ...  We claim that based on the pattern of colors on C, each vertex of degree 3 or more in H is adjacent to a vertex of degree 2 in H.  ... 
arXiv:1909.07503v1 fatcat:6nx6jawzs5cdjizaa64pfasp2e

Compositories and Gleaves [article]

Cecilia Flori, Tobias Fritz
2016 arXiv   pre-print
This generalizes the conditional product structures of Dawid and Studený, which correspond to gleaves on distributive lattices.  ...  Examples of compositories include nerves of categories and compositories of higher spans.  ...  Research at Perimeter Institute is supported by the Government of Canada through Industry Canada and by the Province of Ontario through the Ministry of Economic Development and Innovation.  ... 
arXiv:1308.6548v3 fatcat:jztb6azvljexjcq4vhlcmaexda

The multiplicative rationals

D.K Harrison
1987 Journal of Algebra  
For the second axiom we need the group Y (or more precisely, Y(A)) which is the direct sum (i.e., coproduct) of: copies of Z" one for each u E R, and copies of Z, one for each UE V.  ...  We will work with four levels of complexity: a "system," an "augmented system," a "covered augmented system," and a "bicovered augmented system."  ...  One easily checks the equivalence of this description with the definition. We point out that we have no mention of addition.  ... 
doi:10.1016/0021-8693(87)90179-7 fatcat:afujleg6rjd2jhwuxkw6zt73gq

On λ-covers of pairs by quintuples: ν odd

W.H Mills, R.C Mullin
1994 Journal of combinatorial theory. Series A  
Proof Clearly a (k, 2) cover of index 2 can be obtained by adjoining the blocks of an appropriate 2-cover on w points to the blocks of the incomplete 2-cover. | Now let v and w be positive integers, v  ...  An exact ICa(v, w) is a triple (V, W, F), where V is a v-set, W is a w-subset of V, and F is a family of 5-subsets of V (called blocks) which satisfy (ii) and  ...  The set W is referred to as the hole of the incomplete cover. We adopt the natural convention that B~ (3)  ... 
doi:10.1016/0097-3165(94)90015-9 fatcat:qkr7z2kpmzc77oa7msh3r4a7lu

Page 5162 of Mathematical Reviews Vol. , Issue 2004g [page]

2004 Mathematical Reviews  
G. (3-MB-C; Winnipeg, MB More on exact bicoverings of 12 points. (English summary) Ars Combin. 69 (2003), 197-213.  ...  “In this paper, an outline of the method used to search the weight 12 words of these codes is given. The paper also gives estimations on the size of the search space for the remaining 179 codes.  ... 

Non-adic formal schemes [article]

Takehiko Yasuda
2007 arXiv   pre-print
We also find several examples of non-adic formal schemes.  ...  Our purpose is to make a contribution to the foundation of the theory of formal scheme. We are interested particularly in non-Noetherian or non-adic formal schemes, which have been little studied.  ...  It is equivalent to McQuillan's admissible ring and more general than Grothendieck's one.  ... 
arXiv:0711.0434v1 fatcat:podvhf65e5h7xch3apqknugx7q

Bi-Covering: Covering Edges with Two Small Subsets of Vertices

Amey Bhangale, Rajiv Gandhi, Mohammad T. Hajiaghayi, Rohit Khandekar, Guy Kortsarz
2017 SIAM Journal on Discrete Mathematics  
It was an open problem in [Ambühl et. al., SIAM J. on Comp., 2011] to prove inapproximability of Max-bi-clique assuming weaker conjecture.  ...  For Max-bi-clique problem, a constant factor hardness was known under random 3-SAT hypothesis of Feige [Feige, STOC, 2002] and also under the assumption that NP ∩ >0 BPTIME ( 2 n ) [Khot, SIAM J. on Comp  ...  We would like to thank anonymous reviewers for their comments which significantly helped in improving the presentation of this paper.  ... 
doi:10.1137/16m1082421 fatcat:qdriqyy33vhyjaxmyttgknn2m4

Cohomology with values in a sheaf of crossed groups over a site [article]

Raymond Debremaeker
2017 arXiv   pre-print
I thank the University librarians for sending me a copy of this text and Professor Debremaeker for allowing me to post this translation of his dissertation on this server.  ...  Work on this translation was supported by Chile's Fondecyt through grants 1120003 and 1160004.  ...  Finally, we can verify that the following sequence of pointed sets is exact 1 → H 0 (A) u (0) −→ H 0 (B) v (0) −→ H 0 (C) d −→ H 1 (A) u (1) −→ H 1 (B) v (1) −→ H 1 (C) For more details we refer to [14  ... 
arXiv:1702.02128v1 fatcat:vy63qdybujcf3gcp3gyaz6nsja

Partial-isometric crossed products of dynamical systems by left LCM semigroups [article]

Saeid Zahmatkesh
2022 arXiv   pre-print
theorem as it behaves well under short exact sequences and tensor products.  ...  Let P be a left LCM semigroup, and α an action of P by endomorphisms of a C^*-algebra A. We study a semigroup crossed product C^*-algebra in which the action α is implemented by partial isometries.  ...  Then, C * bicov (P × S) ≃ C * bicov (P ) ⊗ max C * bicov (S). (5.21) Proof.  ... 
arXiv:2008.13097v3 fatcat:byiszj4khrgq7cvxiagkarcqem

A probabilistic construction of small complete caps in projective spaces [article]

Daniele Bartoli, Stefano Marcugini, Fernanda Pambianco
2014 arXiv   pre-print
In this work complete caps in PG(N,q) of size O(q^N-1/2^300 q) are obtained by probabilistic methods.  ...  This gives an upper bound asymptotically very close to the trivial lower bound √(2)q^N-1/2 and it improves the best known bound in the literature for small complete caps in projective spaces of any dimension  ...  In [9] the authors obtain caps of size (k + 1)q N −2 2 in AG(N, q) when the k-arc A is almost bicovering, that is, a complete arc which bicovers all points in AG(2, q) \ A but one.  ... 
arXiv:1406.5060v1 fatcat:4bcb4duoe5dhvmfxsouqmf7rpe

Page 300 of Forest and Stream; A Journal of Outdoor Life, Travel, Nature Study, Shooting, Fishing, Yachting Vol. 56, Issue 15 [page]

1901 Forest and Stream; A Journal of Outdoor Life, Travel, Nature Study, Shooting, Fishing, Yachting  
One more shoot closes our pigeon series, and then for the bluerocks. The annual meeting of the club was held on Wednesday, April 3.  ...  A, rules to govern, with following exceptions: Targets to be thrown not less 40 nor more than 60yds. Targets to be thrown not lower than 6ft., nor higher than 10ft. at a point 10yds. from the trap.  ... 

Donaldson theory on non-Kählerian surfaces and class VII surfaces with b_2=1 [article]

Andrei Teleman
2007 arXiv   pre-print
The main idea of the proof is to show that a certain moduli space of PU(2)-instantons on a surface X with no curves (if such a surface existed) would contain a closed Riemann surface Y whose general points  ...  Then we pass from a family of bundles on X parameterized by Y to a family of bundles on Y parameterized by X, and we use the algebraicity of Y to obtain a contradiction.  ...  Acknowledgments: I am grateful to Nicholas Buchdahl and Matei Toma for their encouragements and for the useful discussions we had on the preliminary version of the article.  ... 
arXiv:0704.2638v1 fatcat:usdkuuefbjczrnpj3ej65objo4

Foundations for almost ring theory -- Release 7.5 [article]

Ofer Gabber, Lorenzo Ramero
2018 arXiv   pre-print
The central result is the "almost purity theorem", for whose proof we adapt Scholze's method, based on his perfectoid spaces.  ...  This is release 7.5 of our project, aiming to provide a complete treatment of the foundations of almost ring theory, following and extending Faltings's method of "almost etale extensions".  ...  In the following, we will write just T(γ) in place of T K (γ), unless we have to deal with more than one base ring. (a) F is h-flat at the point x.  ... 
arXiv:math/0409584v13 fatcat:m6vz44xeefevbn5g6uprzrrujm

Motives of Deligne–Mumford stacks

Utsav Choudhury
2012 Advances in Mathematics  
Without the properness condition we show that M(F) is a direct summand of the motive of a smooth quasi-projective variety.  ...  When F is proper over a field of characteristic 0, we compare M(F) with the Chow motive associated to F by Toen (2000) ([31] ).  ...  The idea of the proof of Theorem 4.3 was entirely communicated by him. I also thank A. J. Scholl for discussions about [29] and A. Kresch for answering questions on stacks.  ... 
doi:10.1016/j.aim.2012.08.012 fatcat:rd2klwc35ndsjnucu3vqpf44ne

Motives of Deligne-Mumford Stacks [article]

Utsav Choudhury
2012 arXiv   pre-print
Without the properness condition we show that M(F) is a direct summand of the motive of a smooth quasi-projective variety.  ...  When F is proper over a field of characteristic 0, we compare M(F) with the Chow motive associated to F by Toen (t).  ...  Denote (△ op P Sh(Sm/k)) • the category of pointed spaces, i.e., presheaves of pointed simplicial sets on Sm/k.  ... 
arXiv:1109.5288v3 fatcat:gmabcjt24je2nl6jbzvy2qo6au
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