2
votes
1answer
123 views
Lower bounds on derivative around zero set of a positive smooth function.
As part of a different problem, I came across the following simplified question, for which I cannot exhibit a proof nor a counterexample. Note that the assumptions of smoothness an …
-1
votes
0answers
85 views
Tight Upper/Lower bound for Incomplete Gamma function
Does anyone know of any tight upper/lower bound for incomplete Gamma functions? i.e either of the following functions:
$$
\Gamma(s,x) = \int_x^{\infty} t^{s-1}\,e^{-t}\,{\rm d}t
…
0
votes
0answers
55 views
Some general theory behind lower bounds ?
Hello
Is it possible to decide whether a given or calculated lower bound is the optimal solution for a problem, like a Arc Routing Problem? If yes, when is a lower bound the optim …
0
votes
0answers
44 views
Kernel with respect mean distances on a unit sphere
I am trying to understand a proof by G.Wagner in his paper "On Means on Distances on the Surface of a Sphere (Lower Bounds)":
http://projecteuclid.org/DPubS/Repository/1.0/Dissemin …
0
votes
1answer
103 views
Good lower bound on matching in bipartite graph
Suppose a bipartite graph $G=(V_1 \cup V_2, E)$ is given, and one is interested in matching vertices $V_1$ to vertices $V_2$. Assume Hall's condition does not hold, so a perfect ma …
3
votes
1answer
191 views
Simple lower bounds for Bell numbers (number of set partitions)?
The $n$-th Bell number $B_n$ represents the number of distinct partitions of a set with $n$ distinguished elements.
It can be expressed as the infinite sum $B_n = (1/e)\sum_{k=1}^{ …
0
votes
0answers
58 views
Proving that a function is maximized over an interval when a variable vanishes at a potential critical point
I recently came across an interesting expression:
$$f = \frac{X\cdot b\cdot\left(\frac{a}{a+b}\right)^X}{a}$$
Where we have the following constraints: $0 < (a,b) < 1$, $(a …
2
votes
0answers
47 views
Lower asymptotic bounds for the derivative of Laguerre polynomials
Let $ L_{d}^{(1)}(x)$ denote the generalized Laguerre polynomial of degree $d$ and order $\alpha=1$. Clearly, since all the roots $r_1,\dots,r_d$ of $L_{d}^{(1)}$ are simple, there …
5
votes
0answers
236 views
Bounding the probability that a random variable is maximal
Suppose we have $N$ independent random variables $X_1$, $\ldots$, $X_N$ with finite means $\mu_1 \leq \ldots \leq \mu_N$ and variances $\sigma_1^2$, $\ldots$, $\sigma_N^2$. I am lo …
5
votes
2answers
282 views
bound for zeros of a polynomial with bounded integer coefficients
Let $f$ be a monic polynomial with bounded integer coefficients and such that all zeros are (in absolute value) greater than $1$. How close can the zeros of $f$ reach $1$ (in ab …
3
votes
2answers
713 views
tight bounds on probability of sum of laplace random variables.
Are there tight upper and lower bounds on the density of the sum of $n$ i.i.d laplace random variables that depend on $n$ and the individual laplacian densities?
0
votes
1answer
272 views
Zorn’s lemma vs Least Upper Bound axiom [closed]
I am confused by the Zonrn's lemma and Least Upper Bound axiom:
(1) Least upper bound axiom: every subset of real number if has an upper bound then has a least upper bound.
(2) Z …
2
votes
2answers
301 views
lower bound for $\Re\zeta(1+it)$
Hi
is there any lower bound for $\Re\zeta(1+it)$.
I did try with computer until some ordinate and I saw $\Re\zeta(1+it)>0$.
If it is true, is there any reference to prove it.
t …
14
votes
6answers
2k views
Lower bounds for chromatic number of a graph
I am trying to find a good lower bound for chromatic number of one family of graphs. I'm curious what are the known lower bounds for chromatic number. There are two obvious: $\chi( …
1
vote
0answers
97 views
Bounding the Schur’s complement of similiar matrices
Assume the following:
• $L\leq K$
.
• $\Gamma\in M_{K,L}$ is a $L$ rank ${ 0,1} $ matrix, without identical rows or the zeros row.
• $N\in M_{K,K}$ is a diagonal matrix, whose …

