Let $G(V,E)$ be an undirekted $k$-vertex-connected, $k$-regular graph  

and let $F$ be an $f$-factor of $G$ consisting of a set of $f$-vertex-connected components, $f<k$. 



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> **Question:**  
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>  what is the vertex-connectivity of $G\setminus F$, is it $k-f$, resp., what is the highest lower bound on the resulting vertex-connectivity?
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Graph connectivity after deleting an f-factor
Make $G$ from two highly-connected pieces joined by a matching of $k$ edges. It has connectivity $k$. Now take $F$ to be a perfect matching that includes the edges of the cut. $G\setminus F$ is then disconnected. So there is no general lower bound except 0.


