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09:13
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Q: What does it mean by linked group action?

LLLLet $V$ be a $k$ -partite set means $V = V_1 \cup V_2 \cup \cdots \cup V_k $. Let $ G \le Sym(V_1) \times \cdots \times Sym(V_k)$ be a direct product group. Now consider the group action of $G$ on set $V$ (assume it is transitive on each $V_i$): $$\pi : G \times V \mapsto V$$ Then each $V_i$ ha...

LLL
LLL
@ anon I have edited the question
I am not sure how you can get blocks on which $G$ acts as either a symmetric or alternating group. I mean, what if you just have the cyclic group of order $p$ (for some prime $p$) acting in the obvious way on a set with $p$ elements?
LLL
LLL
@ Tobias Kildetoft There is an algorithm I have given in the reference section to get minimal block system.
I guess I just don't understand what you mean by $G$ acting on a block system as either a symmetric or an alternating group.
LLL
LLL
$G \times \{B_1,B_2,\cdots B_k\} \mapsto \{B_1,B_2,\cdots B_k\} $, here $G$ is going to be symmetric or an alternating group ( $G$ is a direct product group )
09:13
But again, if I give you $G = C_p$ as above, how could that ever be the case?
Hi
LLL
LLL
hi
This problem is related to graph isomorphism in that place we don't talk about cyclic group. $G = C_p$ I am not able to see any problem
How can that group act as a symmetric or alternating group on anything?
LLL
LLL
act as a symmetric group just means $G = Symmetric $ group .
Right, but you never assumed that $G$ was a symmetric group, just a subgroup of a direct product of symmetric groups
LLL
LLL
yes so
09:20
So $G$ need not be anything like a symmetric group
LLL
LLL
one more condition on $G$, $G \le S_d$ 1) $G$ is either $S_d$ or $A_d$ 2) $\c < d <n$ where c = max \{7, 2 sqrt(n)\}
Do you mean that each of the factors of $G$ is assumed to be either the full symmetric group on that set or the alternating group on the set?
LLL
LLL
yes

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