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BettiBounds :: bettiBounds

bettiBounds -- Compute the Betti bounds

Synopsis

Description

Computes the Betti bounds for complexes which are obtained by c-1 iterated stellar subdivisions from the boundary complex of a simplex on q+1 vertices.

The procedure can also be applied recursively to lists starting with the Betti numbers L={1,1} of a hypersurface.

The i-th entry of B corresponds to the bound of the i-th Betti number. For example, B#1 is the bound on the number of generators. The first and the last entry of B is always 1. The number of entries of B is c+1.

i1 : bettiBounds(1)

o1 = {1, 1}

o1 : List
i2 : bettiBounds(2)

o2 = {1, 2, 1}

o2 : List
i3 : bettiBounds(3)

o3 = {1, 5, 5, 1}

o3 : List
i4 : bettiBounds(4)

o4 = {1, 11, 20, 11, 1}

o4 : List
i5 : bettiBounds(5)

o5 = {1, 23, 62, 62, 23, 1}

o5 : List

Alternatively one can also do:

i6 : L={1,1}

o6 = {1, 1}

o6 : List
i7 : L=bettiBounds(L)

o7 = {1, 2, 1}

o7 : List
i8 : L=bettiBounds(L)

o8 = {1, 5, 5, 1}

o8 : List
i9 : L=bettiBounds(L)

o9 = {1, 11, 20, 11, 1}

o9 : List
i10 : L=bettiBounds(L)

o10 = {1, 23, 62, 62, 23, 1}

o10 : List

See also

Ways to use bettiBounds :

  • bettiBounds(List)
  • bettiBounds(ZZ)