16
votes
3answers
642 views
“Wild” solutions of the heat equation: how to graph them?
It has long been known that the Cauchy initial-value problem for the
classical heat equation on $\mathbb{R}$ (or $\mathbb{R}^n$) doesn't
have unique solutions, without additional a …
3
votes
0answers
42 views
Heat Kernel Asymptotics with low regularity
Let $M$ be a smooth manifold with Riemannian metric $g$, which is not smooth but only continuous.
Question: Is there still an asymptotic expansion of the heat kernel of the form
$ …
5
votes
0answers
82 views
Heat Kernel Asymptotics on Manifold with Boundary
This is crosspost from math.stackexchange http://math.stackexchange.com/questions/311213/heat-kernel-asymptotics-on-manifold-with-boundary where the question did not yield any answ …
5
votes
1answer
164 views
Asymptotic Expansion of the Schrödinger kernel?
My stackexchange post [http://math.stackexchange.com/questions/275830/schrodinger-kernels-on-manifolds] was somewhat unsatisfactory (also because I may not have stated clear enough …
3
votes
0answers
101 views
Heat kernel proof of Poincaré Hopf
I am familiar with Witten's proof of the Morse inequalities by semiclassical analysis. Hey uses semiclassical expansions of the first eigenfunctions to construct the Morse complex …
0
votes
0answers
248 views
heat equation equilibrium temperature [closed]
Consider a uniform bar of length L which has been insulated both ends. If the inital temperature is given by u(x,0)=f(x) (some general distribution), and there is a constant, nonze …
4
votes
3answers
266 views
Reference for estimation gaussian of the heat kernel
Let $(M,g^{TM})$ a Riemannian manifold of dimension $n$ and $\Delta$ the Laplace–Beltrami operator. I would like to find a reference (analytic or probabilistic) for the following c …
0
votes
0answers
156 views
Equilibrium temperature distribution [closed]
Determine the equilibrium temperature distribution, if it exists, for each of the folowing problems. Specify values/ranges for A if necessary.
$\frac{\partial u}{\partial t} = \fr …
1
vote
1answer
447 views
Solution of Heat equation with Neumann BC in an arbitrary domain
Consider the heat equation $u_t=\Delta u$ with Neumann boundary condition and initial condition $u(x,0)=u^0(x)$ in a bounded domain $\Omega$ with smooth boundary.
Is this true:
A …
25
votes
1answer
2k views
Unconditional nonexistence for the heat equation with rapidly growing data?
Consider the initial value problem
$$ \partial_t u = \partial_{xx} u$$
$$ u(0,x) = u_0(x)$$
for the heat equation in one dimension, where $u_0: {\bf R} \to {\bf R}$ is a smooth ini …
4
votes
1answer
573 views
Non-uniqueness of solutions of the heat equation
For the heat equation $(\partial_t-\partial_x^2)f(t,x)=0$ defined on $[0,T)\times(-\infty,\infty)$, to obtain uniqueness of the initial value problem, usually it is required to lim …
4
votes
2answers
469 views
How do you solve linear systems whose solutions decay exponentially?
Consider the heat equation
$$\dot{u} = \Delta u$$
with initial conditions
$$u_0 = \delta(x)$$
for some point $x$ in the domain $\Omega$ of the problem. If $\Omega$ is $\mathbb …
0
votes
0answers
248 views
Heat transfer via black garden hose [closed]
I want to run water through a black hose to increase the water's temperature via the sun. Is there a hose placement pattern that would maximize the surface area available to the s …

