The asymptotics tag has no usage guidance.

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108 views

### Asymptotics of subgraph densities in graphons

In Pittel (1989)'s solution to a problem of Knuth (1976) on the expected number of stable matchings between $n$ men and $n$ women under uniform random preferences, it was shown that, as $n \to \infty$,...

**0**

votes

**1**answer

75 views

### Behavior of a Solution of a Nonlinear ODE

In my work, I encountered the following equation:
$$
(a'(x)+1)^2+k^2(x) a^2(x)=1,\;\;k(x)=2 {\mbox{sech}}(x).
$$
I would like to know as much as possible about the solution. More particularly, I would ...

**4**

votes

**2**answers

169 views

### A Stochastic Taylor Expansion/Asymptotics

Question:
Let $B(t)$ be the standard Brownian motion, $\mu(t,x)$ and $\sigma(t,x)$ are continuous functions, and
$$dr(t) = \mu(t,r(t))dt+\sigma(t,r(t))dB(t).$$
$(\mu,\sigma)$ obeys the linear growth ...

**3**

votes

**0**answers

169 views

### Effective prime number theorem

The prime number theorem implies that for every $ϵ>0$, there is $n_\epsilon$ such that for all $n≥n_\epsilon$ the number of primes in $[n,cn]$ is at least $\frac{(c−1−\epsilon)n}{\log n}$ and at ...

**1**

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**0**answers

61 views

### The Franca-Leclair approximation does not exactly approximate the Riemann zeta zeros but rather the points where only the real part of zeta is zero

Am I right that the Franca-Leclair approximation is a better approximation to the points on the critical line where the real part of the Riemann zeta function is zero and the imaginary part of log ...

**4**

votes

**1**answer

140 views

### What explains the asymptotic and the pattern in this sequence related to Riemann zeta zeros?

As the starting point for my experiment I assumed that the imaginary parts of the Riemann zeta zeros are of the form:
$$\Im \{ \rho_n \} = \frac{2\pi}{\log x_n}$$
where $x_n$ is unknown. Therefore I ...

**3**

votes

**0**answers

63 views

### Fraction of graphs with bound on number of perfect matchings

Asymptotically what is the fraction of balanced bipartite graph on $2n$ vertices with at most $cn^{\beta}$ edges having at most $n^\alpha$ perfect matchings for any fixed $c,\alpha>0$ and fixed $\...

**2**

votes

**0**answers

88 views

### Growth of inner products between two random vectors on the sparse hypercube

We define the $s$-sparse hypercube in $\mathbb{R}^d$ as
\begin{align}
\mathbb{H}_s = \bigl \{ {\bf{v}} \in \{ -1, 0 , 1\}^d \colon \| {\bf{v}} \|_0 = s \bigr\},
\end{align}
where $ \| {\bf v} \|_0 $ ...

**1**

vote

**1**answer

67 views

### Lower Matuszewska index of positive increasing $O$-regular functions

I am not sure if this question is too specific on notations (I think the question is intuitive, but basically the only reference I know with this kind of notations is Bingham, Goldie & Teugels ...

**2**

votes

**1**answer

86 views

### Estimating $\left(\Gamma\left(\frac{\alpha}{\sqrt n}\right)\right)^n$ for fixed $\alpha >0$ as a function of (large) $n$ [closed]

I am interested in the growth of
$$f_\alpha(n)=\left(\Gamma\left(1+\frac{\alpha}{\sqrt{n}}\right)\right)^n,$$
for positive $\alpha$ and large $n$.
(Preferably something more precise than $1! \leq f_\...

**1**

vote

**2**answers

157 views

### aproximate sum involving binomial coefficients

I have the problem for computing the j-derivative of a logarithm, with $j\gg1$
\begin{equation}
c_j=\left.\frac{\partial^j}{\partial s^j}\log\left(1+Ae^s+Be^{2s}\right)\right|_{s=0},
\end{equation}
...

**5**

votes

**1**answer

333 views

### About the logarithmic derivative of the Riemann zeta function

Let $\rho=\beta+i\gamma$ a non-trivial zeros of the Riemann zeta function and $s=\sigma+it$ a complex number. It is possible to prove that $$\frac{\zeta'}{\zeta}\left(s\right)=\sum_{\left|t-\gamma\...

**2**

votes

**0**answers

101 views

### Hypergeometric function asymptotics

I came across the following hypergeometric function recently:
$$
_2F_1(1-n,p-2n+1;p-n+1;x)
$$
where $p > 0$ is a non-integer constant, $n$ some large positive integer, and $x > 0$ a small ...

**2**

votes

**1**answer

68 views

### Regularized integral and asymptotic expansion

Let $f:(0, \infty) \longrightarrow (0, \infty)$ be a monotonously increasing function (in fact, a step function) and let $P$ be a polynomial of degree $N$. Suppose I know that for some $k$, the limit
$...

**1**

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**0**answers

28 views

### Name for a linear space of functions closed under inequalities

Consider $D$ a set and $X$ a linear space of functions $D \rightarrow \mathbb{R}$ s.t. for any $f \in X$ and $g: D \rightarrow \mathbb{R}$, if $\lvert g \rvert \leq \lvert f \rvert$ then $g \in X$. ...

**7**

votes

**1**answer

185 views

### Asymptotics of a special function

In my research, I came up with a special function which I denote by $B(q)$ and is defined by the integral
$$B(q)\equiv \int_{-\pi/2}^{\pi/2} \frac{\sin\left(\frac{q}{2}\tan\theta\right)}{\sin\theta}d\...

**7**

votes

**2**answers

398 views

### Asymptotics of product of Euler's totient function (A001088)?

Conjecture:
\begin{align}
\lim_{n\to \infty } \, \frac{\left(\prod _{k=1}^n \phi (k)\right){}^{1/n}}{n}\sim 0.2059\text{...}
\end{align}
The numerical result from 100000 terms is:
My questions ...

**11**

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**2**answers

657 views

### What is the probability that two random permutations have the same order?

I am interested in the orders of random permutations. Since the law of the logarithm of the order of a permutation converges to a normal law (for instance Erdös-Turan Statistical group theory III), ...

**1**

vote

**1**answer

297 views

### Asymptotics of “ugly” function elucidate Goldbach's conjecture?

Question
We now define the following "ugly" function:
$$ A_c(s,r,n,m) =
\begin{cases}
1 & \text{ if only $sr+nm=2c$ } \\ 0 & \text{otherwise}
\end{cases}
$$
How does the "ugly"...

**1**

vote

**0**answers

54 views

### Asymptotic growth of $f(x) = 2f(x/2 + x/\ln(x))$

In this paper on the Akra–Bazzi theorem, Tom Leighton mentions in his remark at the bottom of page 8, that a function on the positive reals satisfying $f(x) = 2f(x/2 + x/\ln(x))$ for large enough $x$ ...

**9**

votes

**2**answers

218 views

### Asymptotics of functional of i.i.d. Rademacher random variables

Let $X_1,\ldots, X_n$ be i.i.d. Rademacher random variables. That is, $\operatorname{Pr}(X_i = 1) = \operatorname{Pr}(X_i = -1) = 1/2$. I was wondering if the following argument is true:
$$
\mathbb{E} ...

**3**

votes

**1**answer

57 views

### Redundancy in transseries representation of functions?

"Transseries" are a kind of generalized power series that allow things like fractional exponents and exponentials (with another transseries as the exponent). I know very little about them but I have ...

**5**

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**2**answers

207 views

### Alternating binomial Dirichlet series

I have come across the following deceptively simple expression:
$$ H_n^s=\sum_{j=1}^n(-1)^{j-1}\left(\begin{array}{c}n\\j\end{array}\right)j^{-s} $$
We have (using eg mathematica, though probably ...

**5**

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**0**answers

145 views

### Has anyone studied a transport equation of this form?

Let $L\colon \mathbb{R}^2 \times \mathbb{R}^+\to \mathbb R$ satisfy
$$
\frac{\partial L}{\partial t} (x,t) = \max\left\{ \frac{\partial L}{\partial x_1}, \frac{\partial L}{\partial x_2} \right\}
$$
...

**5**

votes

**1**answer

217 views

### Estimating size of greatest prime divisor of a sequence of integers

Consider the numbers of the form: $$A_n = \prod_{\pm}\left(\pm 1\pm \sqrt{2} \pm \cdots \pm \sqrt{n}\right)$$
where, the product in taken oven all $2^n$ terms with variations in sign. We know such ...

**6**

votes

**2**answers

158 views

### Asymptotics of a recursion

suppose we have the following two sequences
$$\alpha_k = (k-1)\left(1-\frac {1}{1+(k+1)l}\right) \quad , k \geq 2$$
$$\beta_k = (k-1)\left(1+\frac {1}{1+(k-1)l}\right) \quad , k \geq 2$$
where $l$...

**9**

votes

**2**answers

267 views

### Asymptotic growth rate of coefficients of generating function

how to calculate the asymptotic growth rate of coefficients generating function $T(z)$ satisfied this identity
$T(z)=z+\frac{T(z)^3}{6}+\frac{T(z^2)T(z)}{2}+\frac{T(z^3)}{3}$

**2**

votes

**1**answer

155 views

### Proofs of inequalities used by Erdos-Renyi in their Random Graphs Paper 1

Please refer to this, it is Erdos-Renyi 1959 paper 1 on Random Graphs. I am currently working on this, but I am stuck on the fifth page, where they use two estimates. More specifically, here's the ...

**0**

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**0**answers

55 views

### Optimal growth of an oscillating integral

Let $f\in H^1(\mathbb{R}^3)$, with $f\equiv0$ inside a ball around the origin. For $t>0$, consider the following integral
$$I(t):=\int_{\mathbb{R}^3}e^{i|x|^2/t}\frac{f(x)}{|x|}dx$$
It`s easy to ...

**1**

vote

**0**answers

103 views

### An analytic family of in fact non-existent improper Riemann integrals

Question:
Are there any useful interpretations or "applications" of the formula
$$\intop_0^\infty e^{-ax}\frac{\sin x}{x}\,dx=\frac{\pi}{2}-\arctan(a)\qquad \forall\;a\in \mathbb{R},
$$
in which the ...

**6**

votes

**1**answer

159 views

### Extension of Wigner's semicircle law?

It is well-known that the semicircle law holds for a wide class of matrices with independent and identically distributed (mean zero) entries.
My question is: is there any study about the more general ...

**2**

votes

**0**answers

90 views

### Number of multipartite partitions with odd components

For some positive integer $r$, by an $r$-vector I will mean an $r$-tuple $(a_1,a_2,\dots,a_r)$ with $a_1,\dots,a_r$ nonnegative integers not all zero, and I will call it odd if $a_1,\dots,a_r$ are all ...

**1**

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72 views

### Asymptotics of a elliptic pde when exponent gets large

I am interested in the following pde
$$ -\Delta w_p + \left( \frac{1}{p-2} +1 \right) \frac{ | \nabla w_p|^2}{w_p} + \epsilon(p) \left( \frac{1}{w_p} \right)^{(p-2)} = (p-2) w_p $$ in the unit ball $...

**1**

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**0**answers

91 views

### Bounds on the number of zeros of a quadratic form

Let $Q(x_1, \dots, x_n)$ be a non-degenerate indefinite quadratic form with integer coefficients. Let $N(Q,T)$ be the set of vectors $x=(x_1, \dots, x_n) \in {\mathbb Z}^n$ such that $|x|<T$ and $Q(...

**16**

votes

**2**answers

828 views

### Probability of two vectors lying in the same orthant

Let $S^{d-1} = \{x \in \mathbb R^d: \|x\| = 1\}$ denote the unit sphere in $\mathbb R^d$. Let $v$, $w$ be drawn uniformly at random from $S^{d-1}$, conditioned on their inner product being equal to $\...

**2**

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**0**answers

38 views

### Asymptotic expansion of Mellin transform of products of modified Bessel function K

Let $n\ge 1$ be an integer, let
$$F(x,y)=\int_0^\infty u^{n(x+y)} (K_{x-y}(u))^n du$$
for $x,y\ge 0$.
When $n=1$, this is just Mellin transform of the Bessel K function. When $n=2$, $F(x,y)$ has ...

**2**

votes

**2**answers

109 views

### Zeros of partial sums of $(1+z)/(1-z)$ near $z=-1$

Let $p_n(z)$ be the $n^\text{th}$ partial sum of the Maclaurin series for $f(z) = (1+z)/(1-z)$. For large $n$ the zeros of $p_n$ appear to avoid the point $z=-1$:
Figure: Zeros of $p_{40}$ and the ...

**2**

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70 views

### Combining oscillatory integrals of the first and second kind

Consider an oscillatory integral of the first kind
$$
I_\lambda(x)=\intop_{\mathbb{R}^{n}}e^{i\lambda\Phi(x,y)}a(x,y)\,d y,\quad \lambda\geq 0,\; a\in C_c^\infty(\mathbb{R}^{k+n}),\; \Phi\in C^\infty(\...

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384 views

### Can you simplify (or approximate) $\sum_{n=0}^{N-1} \binom{N-1}n \frac{(-1)^n}{n+1} e^{-\frac{n}{2(n+1)}\lambda}$?

Let $\binom x y$ be the binomial coefficient. I am trying to get a better understanding of the sum
$$
f(N,\lambda)=\sum_{n=0}^{N-1}\binom{N-1}n\frac{(-1)^n}{n+1} e^{-\frac{n}{2(n+1)}\lambda}
$$
as a ...

**1**

vote

**0**answers

105 views

### Laplace method with “bad” zero set

It is well-known that if $\phi:\mathbb{R}^n \longrightarrow \mathbb{R}$ is a function with $\phi(0) = 0$, $\phi(x)>0$ if $x \neq 0$ and $D^2\phi(0) \geq 0$, then the integral
$$\int_{\mathbb{R}^n} ...

**3**

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61 views

### Equidistribution of Brillouin zones

Answering the question about Limiting shape for Brillouin zones Victor Kleptsyn proved that $N$th Brillouin zone is very close to a circle of radius $c\sqrt N$ (you can find all necessary definitions ...

**3**

votes

**2**answers

157 views

### The minimal growth rate of the countable family of sequences

Let us consider a countable set of sequences of positive numbers $\{(x_n^{(1)}),(x_n^{(2)}),\dots\}$ for which we have
$(\forall k\in\mathbb{N}) \ \lim_n x_n^{(k)} = +\infty$, and
$(\forall k\in\...

**2**

votes

**0**answers

154 views

### On sets of coprime numbers

We know that from prime number theorem that the number of primes below $n$ and above $\frac n2$ (denoted by $\pi_{n,\frac n2}$ is approximately $$\pi_{n,\frac n2}\approx\frac{n}{2\ln n}.$$
Denote by $...

**1**

vote

**1**answer

206 views

### A classification of (reasonable) asymptotics

Notations: "eventually" means "for $x$ sufficiently large"; "positive" means "strictly positive".
Let $\exp_1 = \exp$ and $\exp_{n+1} = \exp_n \circ \exp$.
Let $E$ be the set of smooth function $f: ...

**3**

votes

**1**answer

98 views

### Number and asymptotic for cyclic sequences

Cyclic sequence is equivalence class of cyclic shift action.
If $a = (a_1, ... , a_i)_c$ is cyclic sequence then $(a_1, a_2, \ldots a_{i-1}, a_i)_c = (a_2, a_3, \ldots, a_i, a_1)_c = \ldots = (a_i, ...

**3**

votes

**1**answer

140 views

### Asymptotic for binomial sums

Let $S(n, t) = \sum_{k = 0}^n {n \choose k} ^t$.
The task is to find asymptotic behavior of $S(n,5)$, $n \to \infty$.
Asymptotic for $S(n,0)$ and $S(n,1)$ is very simple.
For $S(n,2)$ we can use ...

**6**

votes

**0**answers

128 views

### How distributive are the fake Laver tables?

The Laver table $A_{n}$ is the unique algebra $(\{1,...,2^{n}\},*)$ such that $x*1=x+1$ for $1\leq x<2^{n}$, $2^{n}*1=1$, and $x*(y*z)=(x*y)*(x*z)$.
Let's now replace the Laver table $A_{n}$ with ...

**2**

votes

**1**answer

213 views

### Asymptotic of a sum involving binomial coefficients

Good evening, I'm trying to find an asymptotic of this sum:
$$\sum_{j=0}^n (-1)^j {n \choose j} (n - j)^n = n^n - {n \choose 1} (n - 1)^n + {n \choose 2} (n - 2)^n + ... + (-1)^n {n \choose n} (n - ...

**2**

votes

**1**answer

143 views

### Doubt concerning a sum involving Kummer extension degrees

I'd like to estimate the following sum
$$
\sum_{n\leq x}\frac1{k_n}\;,\qquad x\rightarrow \infty\;,
$$
where
$k_n=[\mathbb{Q}(\zeta_n,a^{1/n}):\mathbb{Q}]$
is the degree of a Kummer extension for a ...

**0**

votes

**0**answers

64 views

### Factorial Sums over Compositions or ``Unlabeled Permutations"

Let $C_n$ denote subset of integer compositions of $n$ and $c=(c_1,c_2,\dots c_n)$
In a divergent sum, the sequence
$$
a_n=\sum_{c\in C_n} \prod_{c_i\in c} c_i!
$$
frequently shows up and one ...