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Jul
17
comment Impact factor Vs Rating of Maths journals
Advanced in Pure Mathematics is also notorious for accepting at least two nonsense SCIgen papers.
Jul
17
comment Impact factor Vs Rating of Maths journals
@Artem yes, it is subtle. Perhaps I should have said that it is famously the case that some C ranked journals accept papers which are computer generated nonsense. Of course, even the best A* journals may on occasion publish work containing substantial gaps, sometimes unsalvageable ones.
Jul
17
comment Impact factor Vs Rating of Maths journals
@artem if you can point to such a publication I'd be interested in seeing it.
Jul
17
comment Impact factor Vs Rating of Maths journals
@Chuks that isn't necessarily an example of bias. The bulletin and the journal are very difference from the transactions.
Jul
17
comment Impact factor Vs Rating of Maths journals
yes, the ranking may change each year. Journals that are not included in the list may be good or not. The reason for exclusion from the list is sometimes a mystery (or an oversight).
Jul
17
answered Impact factor Vs Rating of Maths journals
Jul
16
comment coproduct of lattices preserving filtered property of positive elements
it doesn't have to be the actual categorical coproduct (which I don't think exists). Any reasonable construction that can act like the coproduct in the sense I describe will be fine.
Jul
16
comment Can $x\pi$ be rational?
$1/\pi \cdot \pi$ and $\sqrt 2/ \pi \cdot \pi$ should resolve it for you.
Jul
16
answered a real number as a point
Jul
15
comment Why do we say “radius” of convergence?
Firstly, you are mistaken if you think the interval you mention is not the set of convergence of some function. It is not centered around $c$, but it is centered around some other number. Secondly, the basic facts of converge of power series on the complex plane are not very hard at all. It follows from relatively easy considerations of convergence criteria.
Jul
15
answered Dedekind cuts and multiplication
Jul
15
comment Dedekind cuts and multiplication
alternative definition of the product of Dedekind cuts, or an alternative construction of the reals in which the product is more fluently given?
Jul
9
comment Relationship between groups that have the same group of homomorphisms to another group
You are right Rob. But this is standard CT stuff and if OP is interested, they have a book reference. I agree with you the answer would have been better if I elaborated, but I don't have the time to do that now. Feel free to edit if you wish.
Jul
9
comment Relationship between groups that have the same group of homomorphisms to another group
I suggest Leinster's "Basic Category Theory" for the basics of CT.
Jul
9
answered Relationship between groups that have the same group of homomorphisms to another group
Jul
9
comment Relationship between groups that have the same group of homomorphisms to another group
oh, sure we do, and it's actually a very interesting question. One can ask for the hom sets to be isomorphic as sets, or as groups. One can ask for the isomorphism to hold for more than just a single group $G$. One can ask for naturality conditions.
Jul
9
comment Relationship between groups that have the same group of homomorphisms to another group
what do you mean that the two hom sets are the same? If $A\ne B$, then the two hom sets are never the same.
Jul
9
answered Initial elements in Set and identity
Jul
9
comment Understanding definition of Riemann Integral
I suggest you go back and first fully understand the notion of limit of a function at a point. If you understand that concept, then this notion of integrability won't be so hard.
Jul
9
comment Understanding definition of Riemann Integral
In general you can't say anything about $L$. That is what integration techniques are for. It is possible though to characterise the Riemann integrable functions on a closed interval, i.e., giving a condition that guarantees the existence of an appropriate $L$. A function is Riemann integrable if, and only if, its set of discontinuities is countable.