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-1 votes
1 answer
70 views

How to give this sum a bound?

Let $x,y\in\mathbb{Z},$ consider the sum below $$\sum_{x,y\in\mathbb{Z}\\ x\neq y}\frac{1}{|x-y|^{4}}\Bigg|\frac{1}{|x|^{4}}-\frac{1}{|y|^{4}}\Bigg|,$$ is there anything I could do to give this sum a ...
Chang's user avatar
  • 329
1 vote
2 answers
53 views

Is there an analytic continuation of the Legendre Chi function $\chi_2(z)$ for $z > 1$?

The Legendre Chi function $\chi_2(z)$ is define as $$ \chi_2(z) = \sum_{k=0}^{\infty}\frac{z^{2k+1}}{(2k+1)^2} $$ for $-1 \le z \le 1$. But $z > 1$ the series diverges. For real value of $z$ is ...
Nilotpal Sinha's user avatar
1 vote
0 answers
50 views

Explicit upper bound on $\pi(n)$ (Weak version of PNT)

Chebyshev first proved that there exist constants $a$, $b$ such that $$ a \frac{n}{\log n} < \pi(n) < b \frac{n}{ \log n}.$$ The proof is well understood, and relies on elementary techniques. ...
Navvye's user avatar
  • 57
1 vote
0 answers
58 views

disk of convergence of composition of p-adic functions

I watched a video that sketched out the regions of convergence for both the p-adic logarithm and the p-adic exponential functions. I thought about all this and asked myself: How would I find the ...
zeta space's user avatar
0 votes
0 answers
74 views

Is $\phi_0$ equivalent to the Riemann hypothesis?

This is an extension (and more distilled version) of Extension of PDE's to critical strip, with new information. I am fairly sure that my constructions are an alternate description of the De Brujn ...
zeta space's user avatar
2 votes
1 answer
53 views

Value of a Sum linked with Beta Dirichlet Function and Zeta Function

Recently, I tried to calculate this double sum: $$ F(s) = \sum_{(a,b) \in \mathbb{Z}^2 \backslash (0,0) } \frac{1}{(a^2 + b^2)^s}$$ For $ s \in \mathbb{C}, Re(s) > 1$ I think i found the value of ...
Azoth's user avatar
  • 31
0 votes
0 answers
33 views

Bound for exponential

Let $\displaystyle f(x)= e^{-Ae^x} e^{Bx} \left( 1+ \mathcal{O} \left( e^{-x} \right)\right)$, where $A$ and $B$ are constants. Claim: $|f(x)| = \mathcal{O}\left( \exp(-e^x)\right)$ as $x \rightarrow ...
Richard D's user avatar
  • 177
3 votes
0 answers
90 views

A question on Beukers proof of irrationality of $\zeta(3)$

I am reading the paper A note on the Irrationality of ζ(2) and ζ(3) by F. Beukers. In equation $(7)$, we have $$I_n=\int_{(0,1)^3}\frac{x^n(1-x)^ny^n(1-y)^nw^n(1-w)^n}{(1-(1-xy)w)^{n+1}} dx dy dw \tag{...
Max's user avatar
  • 928
0 votes
1 answer
107 views

Proof of $\sum_{n=1}^\infty a_n n^{-s} = s\int_1^\infty A(x) x^{-s-1}\, dx$ and $\limsup_{x\to\infty} \frac{\log|A(x)|}{\log x} = \sigma_c$

Theorem. Let $A(x) := \sum_{n\le x} a_n$. If $\sigma_c < 0$, then $A(x)$ is a bounded function, and $$\sum_{n=1}^\infty a_n n^{-s} = s\int_1^\infty A(x) x^{-s-1}\, dx \tag{1}$$ for $\sigma > 0$. ...
stoic-santiago's user avatar
1 vote
1 answer
149 views

Question about Salem's integral equation reformulation of Riemann hypothesis

Consider an integral equation: $$\int_{-\infty}^{+\infty}\frac{e^{-\sigma y}f(y)}{e^{e^{x-y}}+1}dy=0$$, where $\sigma\in(\frac{1}{2},1)$ Salem proved that this equation has no bounded solution other ...
stephan's user avatar
  • 375
1 vote
1 answer
136 views

Divergent sums of reciprocals of specific natural numbers [duplicate]

It is known that $$\sum_{k=1}^n \frac1k \sim \ln(n)$$ and $$\sum_{p \text{ prime}}^n \frac1p \sim \ln(\ln(n)),$$ with the property that the difference in each case converges to a constant (Euler–...
Thrash's user avatar
  • 349
1 vote
1 answer
50 views

Removing a smooth weight

If I understand $$\sum _{n\leq x}a_n(1-n/x)\hspace {5mm}\text {or}\hspace {5mm}\sum _{n\leq x}a_n\log (x/n)$$ then I understand $$\sum _{n\leq x}a_n$$ by writing $$\sum _{n\leq x}a_n=\frac {x+h}{h}\...
tomos's user avatar
  • 1,662
0 votes
1 answer
55 views

is there a notion of natural density over sets of integer with special structure?

Generally, the natural density of a set $A\subseteq \{1, \dots, n\}$, denoted by $d(A)$, is defined as $$d(A)= \lim_{n\to\infty} \frac{\mid A \mid }{n}$$ Now, I am wondering, is there a similar notion ...
vxek's user avatar
  • 197
12 votes
0 answers
351 views

Approximate the sum of a non $C^1(0,1)$ function by its integral

Consider the function $f: [0,1] \to \mathbb{C}$ defined by $$ f(x)=\sum_{n=1}^{9} e^{2\pi n i x}, $$ so that $$ |f(x)|=\bigg|\frac{\sin(9\pi x)}{\sin(\pi x)}\bigg|. $$ I'm interested in approximating $...
Itachi's user avatar
  • 656
1 vote
1 answer
160 views

Residues of $\zeta'(s)/\zeta(s)$ at non-trivial zero of the Riemann zeta function and the order of zeros

I don't understand something about the residues of $\zeta'(s)/\zeta(s)$. I'm studying complex analysis using Stein's Complex Analysis. The zeros of the Riemann zeta function are $-2n$ ($n$ is natural) ...
dontunder's user avatar

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