We determine the smallest irreducible Brauer characters for finite quasi-simple orthogonal type groups in non-defining characteristic. Under some restrictions on the characteristic we also prove a gap result showing that the next larger irreducible Brauer characters have a degree roughly the square of those of the smallest non-trivial characters.

中文翻译：

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有限正交群的低维表示

我们确定了有限准单正交型群在非定义特征中的最小不可约布劳尔特征。在对特征的一些限制下，我们还证明了一个间隙结果，表明下一个较大的不可约 Brauer 字符的度数大致是最小非平凡字符的平方。