The linking number of a loop with itself enters into the calculation of the partition function, but this number is not invariant under small deformations and in particular, is not a topological invariant.
12.
Similarly, the linking number can be defined in terms of intersections, shifting dimensions by 1, or alternatively in terms of a non-vanishing cup product on the complement of a link.
13.
Since the linking number " L " of supercoiled DNA is the number of times the two strands are intertwined ( and both strands remain covalently intact ), " L " cannot change.
14.
Where Lk is the asymptotic ( Gauss ) linking number ( a topological quantity ), Wr denotes the total writhing number ( or simply writhe ) and Tw is the total twist number ( or simply twist ).
15.
Thus in order to compute the linking number of the diagram corresponding to " v " it suffices to count the " signed " number of times the Gauss map covers " v ".
16.
This formulation of the linking number of " ? " 1 and " ? " 2 enables an explicit formula as a double line integral, the "'Gauss linking integral " ':
17.
This number can be rendered well defined if one chooses a framing for each loop, which is a choice of preferred nonzero normal vector at each point along which one deforms the loop to calculate its self-linking number.
18.
They interpreted their data as supporting the possibility that the two strands inside the native DNA double helix are winding ambidextrously rather than plectonemically, with left-handed and right-handed regions coexisting in a zero linking number topoisomer.
19.
Given a framed knot " C ", the self-linking number is defined to be the linking number of " C " with a new curve obtained by pushing points of " C " along the framing vectors.
20.
Given a framed knot " C ", the self-linking number is defined to be the linking number of " C " with a new curve obtained by pushing points of " C " along the framing vectors.
