Bifurcation of critical periods for plane vector fields
Bifurcation of critical periods for plane vector fields
A bifurcation problem in families of plane analytic vector fields which have a nondegenerate center at the origin for all values of a parameter <inline-formula content-type="math/mathml"> <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" alttext="lamda element-of bold upper R Superscript upper N"> <mml:semantics> <mml:mrow> <mml:mi>λ<!-- λ --></mml:mi> <mml:mo>∈<!-- ∈ --></mml:mo> <mml:mrow class="MJX-TeXAtom-ORD"> <mml:msup> <mml:mrow class="MJX-TeXAtom-ORD"> <mml:mrow …