Non-concentration of primes in Γ\PSL2(ℝ)
摘要
This paper generalizes the result of Sarnak and Ubis [9] about non-concentration of primes in horocycle orbits on PSL2(ℤ)PSL2(ℝ) to any lattice in PSL2(ℝ). The proof combines the asymptotic result of Strömbergsson [11] and Venkatesh’s method [12] with the approach of Sarnak and Ubis of approximating horocycle pieces with periodic horocycles. The key step is to establish a dichotomy between {ξh(t), t ∈ [0, T]} having good equidistribution in ΓPSL2 (ℝ) and it being approximable by closed horocycle pieces with small period. In a follow-up paper, a similar approach will be used to show equidistribution of ξh(n1+γ) for small γ > 0, generalizing Venkatesh’s result [12] to non-compact Γ.