1,693,946 research outputs found

    A proof of the Riemann hypothesis based on the Koch theorem, on primes in short intervals, and distribution of nontrivial zeros of the Riemann zeta function

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    Part One: Let define the truncation of the logarithmic integral Li(x)Li(x) as π(x,M)=xlogxn=0Mn!lognx. \pi^{*}(x,M)=\frac{x}{\log x}\sum_{n=0}^{M}\frac{n!}{\log^{n}x}. First, we prove π(x,M)Li(x)<π(x,M+1)\pi^{*}(x,M)\leq Li(x)<\pi^{*}(x,M+1) which implies that the point of the truncation depends on x, Next, let αL,M=xM+1/xM\alpha_{L,M}=x_{M+1}/x_{M}. We prove that αL,M\alpha_{L,M} is greater than ee for M<M<\infty and tends to αL,=e\alpha_{L,\infty}=e as MM \to \infty. Thirdly, we prove M=logx2+O(1) for x24. M=\log x-2+O(1)\texttt{ for }x\geq24. Finally, we prove Li(x)π(x,M)<x for x24. Li(x)-\pi^{*}(x,M)<\sqrt{x}\texttt{ for }x\geq24. Part Two: Let define π(x,N)=xlogxn=0Nn!lognx \pi^{*}(x,N)=\frac{x}{\log x}\sum_{n=0}^{N}\frac{n!}{\log^{n}x} where we proved that the pair of numbers xx and NN in π(x,N)\pi^{*}(x,N) satisfy inequalities π(x,N)<π(x)<π(x,N+1)\pi^{*}(x,N)<\pi(x)<\pi^{*}(x,N+1), and the number NN is approximately a step function of the variable logx\log x with a finite amount of deviation, and proportional to logx\log x. We obtain much more accurate estimation π(x)π(x,N)\pi(x)-\pi^{*}(x,N) of prime numbers, the error range of which is less than x\sqrt{x} for x103x\geq10^{3} or less than x1/20.0327283x^{1/2-0.0327283} for x1041x\geq10^{41}. Part Three: We show the closeness of Li(x)Li(x) and π(x)\pi(x) and give the difference π(x)Li(x)|\pi(x)-Li(x)| being less than or equal to cxlogxc\sqrt{x}\log x where cc is a constant. Further more, we prove the estimation Li(x)=π(x,N)+O(x)Li(x)=\pi^{*}(x,N)+O(\sqrt{x}). Hence we obtain π(x)=Li(x)+O(x)\pi(x)=Li(x)+O(\sqrt{x}) so that the Riemann hypothesis is true. Part Four: Different from former researches on the distribution of primes in short intervals, we prove a theorem: Let Φ(x)=βx1/2\Phi(x)=\beta x^{1/2}, β>0\beta>0, and xxβx\geq x_{\beta} which satisfies (logxβ)2/xβ0.0327283β(\log x_{\beta})^{2}/x_{\beta}^{0.0327283}\leq\beta. Then there are π(x+Φ(x))π(x)Φ(x)/logx=1+O(1logx) \frac{\pi(x+\Phi(x))-\pi(x)}{\Phi(x)/\log x}=1+O(\frac{1}{\log x}) and limxπ(x+Φ(x))π(x)Φ(x)/logx=1. \lim_{x \to \infty}\frac{\pi(x+\Phi(x))-\pi(x)}{\Phi(x)/\log x}=1. Comment: 95 page

    Effect of isoelectronic doping on honeycomb lattice iridate A_2IrO_3

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    We have investigated experimentally and theoretically the series (Na1x_{1-x}Lix_{x})2_{2}IrO3_{3}. Contrary to what has been believed so far, only for x0.25x\leq0.25 the system forms uniform solid solutions. For larger Li content, as evidenced by powder X-ray diffraction, scanning electron microscopy and density functional theory calculations, the system shows a miscibility gap and a phase separation into an ordered Na3_{3}LiIr2_2O6_{6} phase with alternating Na3_3 and LiIr2_2O6_6 planes, and a Li-rich phase close to pure Li2_{2}IrO3_{3}. For x0.25x\leq 0.25 we observe (1) an increase of c/ac/a with Li doping up to x=0.25x=0.25, despite the fact that c/ac/a in pure Li2_{2}IrO3_{3} is smaller than in Na2_{2}IrO3_{3}, and (2) a gradual reduction of the antiferromagnetic ordering temperature TNT_{N} and ordered moment. The previously proposed magnetic quantum phase transition at x0.7x\approx 0.7 may occur in a multiphase region and its nature needs to be re-evaluated.Comment: 8 pages, 9 figures including supplemental informatio

    Average prime-pair counting formula

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    Taking r>0r>0, let π2r(x)\pi_{2r}(x) denote the number of prime pairs (p,p+2r)(p, p+2r) with pxp\le x. The prime-pair conjecture of Hardy and Littlewood (1923) asserts that π2r(x)2C2rli2(x)\pi_{2r}(x)\sim 2C_{2r} {\rm li}_2(x) with an explicit constant C2r>0C_{2r}>0. There seems to be no good conjecture for the remainders ω2r(x)=π2r(x)2C2rli2(x)\omega_{2r}(x)=\pi_{2r}(x)- 2C_{2r} {\rm li}_2(x) that corresponds to Riemann's formula for π(x)li(x)\pi(x)-{\rm li}(x). However, there is a heuristic approximate formula for averages of the remainders ω2r(x)\omega_{2r}(x) which is supported by numerical results.Comment: 26 pages, 6 figure

    A new bound for the smallest xx with π(x)>li(x)\pi(x) > li(x)

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    We reduce the leading term in Lehman's theorem. This improved estimate allows us to refine the main theorem of Bays and Hudson. Entering 2,000,0002,000,000 Riemann zeros, we prove that there exists xx in the interval [exp(727.951858),exp(727.952178)][exp(727.951858), exp(727.952178)] for which \pi(x)-\li(x) > 3.2 \times 10^{151}. There are at least 1015410^{154} successive integers xx in this interval for which \pi(x)>\li(x). This interval is strictly a sub-interval of the interval in Bays and Hudson, and is narrower by a factor of about 12.Comment: Final version, to be published in the International Journal of Number Theory [copyright World Scientific Publishing Company][www.worldscinet.com/ijnt

    Efficient prime counting and the Chebyshev primes

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    The function \epsilon(x)=\mbox{li}(x)-\pi(x) is known to be positive up to the (very large) Skewes' number. Besides, according to Robin's work, the functions \epsilon_{\theta}(x)=\mbox{li}[\theta(x)]-\pi(x) and \epsilon_{\psi}(x)=\mbox{li}[\psi(x)]-\pi(x) are positive if and only if Riemann hypothesis (RH) holds (the first and the second Chebyshev function are θ(x)=pxlogp\theta(x)=\sum_{p \le x} \log p and ψ(x)=n=1xΛ(n)\psi(x)=\sum_{n=1}^x \Lambda(n), respectively, \mbox{li}(x) is the logarithmic integral, μ(n)\mu(n) and Λ(n)\Lambda(n) are the M\"obius and the Von Mangoldt functions). Negative jumps in the above functions ϵ\epsilon, ϵθ\epsilon_{\theta} and ϵψ\epsilon_{\psi} may potentially occur only at x+1Px+1 \in \mathcal{P} (the set of primes). One denotes j_p=\mbox{li}(p)-\mbox{li}(p-1) and one investigates the jumps jpj_p, jθ(p)j_{\theta(p)} and jψ(p)j_{\psi(p)}. In particular, jp<1j_p<1, and jθ(p)>1j_{\theta(p)}>1 for p<1011p<10^{11}. Besides, jψ(p)<1j_{\psi(p)}<1 for any odd p \in \mathcal{\mbox{Ch}}, an infinite set of so-called {\it Chebyshev primes } with partial list {109,113,139,181,197,199,241,271,281,283,293,313,317,443,449,461,463,}\{109, 113, 139, 181, 197, 199, 241, 271, 281, 283, 293, 313, 317, 443, 449, 461, 463, \ldots\}. We establish a few properties of the set \mathcal{\mbox{Ch}}, give accurate approximations of the jump jψ(p)j_{\psi(p)} and relate the derivation of \mbox{Ch} to the explicit Mangoldt formula for ψ(x)\psi(x). In the context of RH, we introduce the so-called {\it Riemann primes} as champions of the function ψ(pnl)pnl\psi(p_n^l)-p_n^l (or of the function θ(pnl)pnl\theta(p_n^l)-p_n^l ). Finally, we find a {\it good} prime counting function S_N(x)=\sum_{n=1}^N \frac{\mu(n)}{n}\mbox{li}[\psi(x)^{1/n}], that is found to be much better than the standard Riemann prime counting function.Comment: 15 pages section 2.2 added, new sequences added, Fig. 2 and 3 are ne

    The Energetics of Li Off-Centering in K1x_{1-x}Lix_xTaO3_3; First Principles Calculations

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    K1x_{1-x}Lix_{x}TaO3_3 (KLT) solid solutions exhibit a variety of interesting physical phenomena related to large displacements of Li-ions from ideal perovskite A-site positions. First-principles calculations for KLT supercells were used to investigate these phenomena. Lattice dynamics calculations for KLT exhibit a Li off-centering instability. The energetics of Li-displacements for isolated Li-ions and for Li-Li pairs up to 4th neighbors were calculated. Interactions between nearest neighbor Li-ions, in a Li-Li pair, strongly favor ferroelectric alignment along the pair axis. Such Li-Li pairs can be considered "seeds" for polar nanoclusters in KLT. Electrostriction, local oxygen relaxation, coupling to the KT soft-mode, and interactions with neighboring Li-ions all enhance the polarization from Li off-centering. Calculated hopping barriers for isolated Li-ions and for nearest neighbor Li-Li pairs are in good agreement with Arrhenius fits to experimental dielectric data.Comment: 14 pages including 10 figures. To Physical Review B. Replaced after corrections due to referees' remark
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