Large values of characters of the symmetric group
Large values of characters of the symmetric group
For
I am interested on upper bounds for characters of the symmetric group that improve slightly on the second bound.
More specifically, fix
Recall that for a permutation
For example, known upper bounds for the dimension of representations of the symmetric group imply there does not exist such a character for
I found works in the literature giving bounds for
K2-Think
To address the question of identifying elements ( g \in S_n ) for which there exists an irreducible character ( \chi ) with ( |\chi(g)| > \sqrt{|Z(g)|} e^{-\delta \sqrt{n}} ) (where ( \delta > 0 ) is small), we analyze the structure of permutations, their centralizers, and character bounds from representation theory.
Key Observations:
- Centralizer Size: For a permutation ( g )...
GPT-5
Write n = ∑k k mk, where mk is the number of k-cycles of g, so |Z(g)| = ∏k (kmk mk!).
Your inequality asks for those g for which there exists some irreducible χ of Sn with |χ(g)| > √|Z(g)| e−δ√n.
There are three simple regimes to keep in mind, which together already give a reasonably sharp picture.
- What averaging already guarantees (for every g) By column orthogonality, ∑χ |χ(g)|^2 = |Z(g)|,...
o3 Pro
The whole problem turns on the size of the centraliser of the permutation
and on the observation that
∑χ |χ(g)|² = |Z(g)| (orthogonality of characters).
Write p(n) for the number of partitions of n ( = the number of irreducible characters of S n ), and fix a constant δ>0. Put
M(g) := maxχ |χ(g)| .
Of course M(g) ≤ √{|Z(g)|}; the question is when we can have
M(g) > √{|Z(g)|} eˉ ...
Gemini 2.5 Pro
This is an excellent question that touches upon some deep results in the asymptotic representation theory of symmetric groups. Your intuition that such characters
Summary of the Answer
The condition $|\chi(g...
o4 mini
Here is a fairly complete picture, which shows that nothing “mystical’’ is hiding here – the only time one can beat the naïve central‐izer bound
- **(Larsen–Shalev and Féray–Śniady boun...
o3
Throughout let
Z(g)=∏k k^{m_k }m_k ! be the order of the centraliser of the permutation
g=1^{m_1 }2^{m_2 }⋯ in S_n (so ∑k km_k =n) and fix a positive
constant δ.
We want to know when there is an irreducible character χ of S_n
such that
|χ(g)| > √Z(g)·e^{-δ√n}. (1)
- A very useful elementary observation
The number c(g)=∑k m_k of cycles of g controls ...
Claude 3.7 Sonnet
Analysis of Large Character Values in the Symmetric Group
The question asks when there exists an irreducible character
Understanding the Condition
This condition is closely related to the formula
DeepSeek R1
First, I need to recall some basics. For a permutation ( g ) with cycle type ( (m_1, m_2, \ld...
Claude Opus 4
This is an interesting question about character bounds for symmetric groups. Let me analyze what's known and what can be said about your specific bound.
The question asks: for which
Key Observations
- The bound is sharp for regular elements: When
is an -cycle, w...
You need to be logged in to submit an answer