No Arabic abstract
Let ${F}_{n}$ be the Farey sequence of order $n$. For $S subseteq {F}_n$ we let $mathcal{Q}(S) = left{x/y:x,yin S, xle y , , textrm{and} , , y eq 0right}$. We show that if $mathcal{Q}(S)subseteq F_n$, then $|S|leq n+1$. Moreover, we prove that in any of the following cases: (1) $mathcal{Q}(S)=F_n$; (2) $mathcal{Q}(S)subseteq F_n$ and $|S|=n+1$, we must have $S = left{0,1,frac{1}{2},ldots,frac{1}{n}right}$ or $S=left{0,1,frac{1}{n},ldots,frac{n-1}{n}right}$ except for $n=4$, where we have an additional set ${0, 1, frac{1}{2}, frac{1}{3}, frac{2}{3}}$ for the second case. Our results are based on Grahams GCD conjectures, which have been proved by Balasubramanian and Soundararajan.
The existence of a set of d^2 pairwise equiangular complex lines (equivalently, a SIC-POVM) in d-dimensional Hilbert space is currently known only for a finite set of dimensions d. We prove that, if there exists a set of real units in a certain ray class field (depending on d) satisfying certain congruence conditions and algebraic properties, a SIC-POVM may be constructed when d is an odd prime congruent to 2 modulo 3. We give an explicit analytic formula that we expect to yield such a set of units. Our construction uses values of derivatives of zeta functions at s=0 and is closely connected to the Stark conjectures over real quadratic fields. We verify numerically that our construction yields SIC-POVMs in dimensions 5, 11, 17, and 23, and we give the first exact solution to the SIC-POVM problem in dimension 23.
This article covers three topics. (1) It establishes links between the density of certain subsets of the set of primes and related subsets of the set of natural numbers. (2) It extends previous results on a conjecture of Bruinier and Kohnen in three ways: the CM-case is included; under the assumption of the same error term as in previous work one obtains the result in terms of natural density instead of Dedekind-Dirichlet density; the latter type of density can already be achieved by an error term like in the prime number theorem. (3) It also provides a complete proof of Sato-Tate equidistribution for CM modular forms with an error term similar to that in the prime number theorem.
We formulate a general super duality conjecture on connections between parabolic categories O of modules over Lie superalgebras and Lie algebras of type A, based on a Fock space formalism of their Kazhdan-Lusztig theories which was initiated by Brundan. We show that the Brundan-Kazhdan-Lusztig (BKL) polynomials for Lie superalgebra gl(m|n) in our parabolic setup can be identified with the usual parabolic Kazhdan-Lusztig polynomials. We establish some special cases of the BKL conjecture on the parabolic category O of gl(m|n)-modules and additional results which support the BKL conjecture and super duality conjecture.
We announce a number of conjectures associated with and arising from a study of primes and irrationals in $mathbb{R}$. All are supported by numerical verification to the extent possible.
Using geometric methods, we improve on the function field version of the Burgess bound, and show that, when restricted to certain special subspaces, the M{o}bius function over $mathbb F_q[T]$ can be mimicked by Dirichlet characters. Combining these, we obtain a level of distribution close to $1$ for the M{o}bius function in arithmetic progressions, and resolve Chowlas $k$-point correlation conjecture with large uniformity in the shifts. Using a function field variant of a result by Fouvry-Michel on exponential sums involving the M{o}bius function, we obtain a level of distribution beyond $1/2$ for irreducible polynomials, and establish the twin prime conjecture in a quantitative form. All these results hold for finite fields satisfying a simple condition.