Thomas Belulovich

Providence, RI

math.brown.edu/~thobel

Age: 26

Mar
25
comment Homotopy equivalences
Hint: denote $G = G_f$ to emphasize the dependence of $G$ on $f$. Suppose $f_1,f_2 : X \to Y$ are homotopic. Can you show $G_{f_1} = G_{f_2}$?
Feb
27
comment Topology with one element
I would read "space with only one element" as the space $X = \{*\}$ with the only topology that it can admit.
Feb
27
comment Does $\sin (5x)=5\sin(x)$? Why or why not?
There should be a few values $x$ for which you are familiar with the value $\sin (x)$. (If there aren't, you should learn a few! Having a few examples/computations to keep in mind when thinking about mathematics is vital. I cannot stress this enough.) Does your conjecture hold for these values?
Feb
26
comment Find out, if $a$ lies on a path from $b$ to the root of the tree.
Please specify what you mean by "meet $a$ and then $b$". Depending on how you do this, your algorithm could be correct or incorrect. (You don't want to accept when $a$ and $b$ are on different branches, but you searched $a$'s branch first.) Also the parameter $m$ doesn't exist for this problem.
Feb
26
comment Diagonalise matrix iff eigenvectors independent (True/False)
@Roland Yes :).
Feb
26
comment Diagonalise matrix iff eigenvectors independent (True/False)
Could you clarify what you mean by "eigenvectors are independent"? There are often infinitely many eigenvectors!
Feb
26
reviewed Edit suggested edit on Alternating Harmonic Series
Feb
26
revised Alternating Harmonic Series
improved clarity
Feb
26
reviewed Reject suggested edit on What is your favorite application of the Pigeonhole Principle?
Feb
26
reviewed Reject suggested edit on What is your favorite application of the Pigeonhole Principle?
Feb
18
awarded Editor
Feb
18
revised How to make the list of lists into a single list by interleaving elements in haskell?
added 524 characters in body
Feb
18
comment How to make the list of lists into a single list by interleaving elements in haskell?
oops! I will make an edit to add in a function that properly stops.
Feb
17
awarded Teacher
Feb
17
answered How to make the list of lists into a single list by interleaving elements in haskell?
Jan
15
reviewed Approve suggested edit on Proof Visualization
Jan
15
reviewed Approve suggested edit on Visualizing a projective variety
Jan
9
comment In category theory, does $X \leq Y$ have a nice characterization in terms of the existence of a morphism $X \rightarrow Y$?
@user18921 $\emptyset \to \emptyset$ factors through $\emptyset$, but cannot possibly factor through $X$ if $X$ is non-empty.
Jan
7
comment Too stupid to understand random variable questions?
The coin toss is uniformly distributed over the discrete set $\{0,1\}.$ I find it can be helpful to think of discrete cases to build intuition a bit.
Jan
7
comment Too stupid to understand random variable questions?
Regarding 1: Take a simpler case; let $X_1$ and $X_2$ be fair coin tosses, where heads=1 and tails=0. What is the distribution of $X_1+X_2$, the random variable gotten by flipping two coins and adding the results? Is it uniform?
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