2
votes
1answer
39 views
Exact solutions to nonlinear Klein-Gordon equation
The nonlinear pde
$$
\partial_t^2\phi-\partial_x^2\phi+\lambda\phi^3=0
$$
has the exact solution
$$
\phi(x,t)=\mu\left(\frac{2}{\lambda}\right)^\frac{1}{4}{\rm sn}(p_0t-p\cdo …
0
votes
0answers
36 views
What is the corresponding version in the complex space of this proposition got in the real space real
How can I transform the following proposition that is gotten in $real$ space into the corresponding one used in the $complex$ space?
Proposition: Let $A\in R^{n\times n}$ be a ma …
45
votes
2answers
5k views
Philosophy behind Yitang Zhang’s work on the Twin Primes Conjecture
Yitang Zhang recently published a new attack on the Twin Primes Conjecture. Quoting Andre Granville :
“The big experts in the field had
already tried to make this approach
…
6
votes
3answers
255 views
What can be said about pairs of matrices P,Q that satisfies $(P^{-1})^T \circ P = (Q^{-1})^T \circ Q$ ?
Let $P,Q$ be $n$ by $n$ invertible matrices. Suppose further that $P$ and $Q$ satisfies the following equation :
$$(P^{-1})^T \circ P = (Q^{-1})^T \circ Q$$
where $\circ$ denotes …
0
votes
0answers
18 views
Computational Ring Theory
I have tried to understand and program CGT algorithms though I am a beginner still. But I never get to hear Computational Ring Theory. Even GAP largely supports Groups Theory. Is t …
10
votes
5answers
1k views
Consistency strength needed for applied mathematics
Given that we can never proof the consistency of a theory for the foundations of mathematics in a weaker system, one could seriously doubt whether any of the commonly used foundati …
-5
votes
0answers
23 views
How important is a Facility Maintenance Software for a small concern like mine? [closed]
How important is a Facility Maintenance Software for a small concern like mine?
http://www.nexgenam.com/
9
votes
4answers
234 views
Why don’t more mathematicians improve Wikipedia articles?
Wikipedia is a widely used resource for mathematics. For example, there are hundreds of mathematics articles that average over 1000 page views per day. Here is a list of the 500 mo …
-4
votes
0answers
97 views
ABC Conjecture Proof. Is it correct? [closed]
SO Prime III. ABC Conjecture PROOF
http://www.one-zero.eu/resources/Z-ABC.pdf
2
votes
2answers
98 views
fixedpoint or fixed point or fixed-point
I am unsure which is the right spelling (if there even is a ‘right’ spelling), but maybe native speakers can enlighten me: When should I use
fixed point
fixed-point
fixedpoint
…
5
votes
2answers
366 views
Probability $k$ bins are non-empty.
The following problem arises in the analysis of Bloom filters.
Consider $m$ bins and $N=nk$ balls placed uniformly at random into the bins. A query chooses $k$ bins uniformly at …
0
votes
1answer
43 views
simple explaination of simplicial volume=4g-4 when genus $\ge 1$
In Gromov's famous book ,it says "simplical volume of every oriented surface of genus $ \ge 1$ satisfies${\left\| {\left[ S \right]} \right\|_\Delta } = 4g - 4 = - 2\chi \left( S …
1
vote
0answers
32 views
mixed Hodge polynomial
Let $X$ be a smooth projective algebraic variety over a field of characteristic zero. Let $U$ be the complement in $X$ of a simple normal crossings divisor $D$. For each degree $k$ …
17
votes
18answers
4k views
What are some applications of other fields to mathematics?
It is commonplace to consider applications of mathematics to other fields, especially the exact sciences. But what I would like to know about is the converse topic, namely:
Wha …
2
votes
1answer
31 views
Counterexample of non-negative sequence weakly converging in $\mathscr{M}^1$ but not $L^1$
Hi.
Consider a a sequence of non-negative functions $(f_n)_n$, bounded in $L^1([-1,1])$ and weakly$-\star$ converging in $\mathscr{M}^1([-1,1])$ to some $f\in L^1([-1,1])$. What I …

