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3 votes
0 answers
193 views

Are local complete intersections of small codimension necessarily (global) complete intersections?

Hartshorne's 1974 conjecture states that a smooth closed subvariety $X$ of $\mathbb{CP}^r$ of dimension $>2/3r$ is necessarily (globally) a complete intersection. Is anything interesting known ...
Mikhail Bondarko's user avatar
21 votes
1 answer
975 views

Conjecture: Given any five points, we can always draw a pair of non-intersecting circles whose diameter endpoints are four of those points

The following question resisted attacks at Math SE, so I thought I would try posting it here. Is the following conjecture true or false: Given any five coplanar points, we can always draw at least ...
Dan's user avatar
  • 3,527
28 votes
3 answers
5k views

Why to believe the Fargues geometrization conjecture?

In the study of the arithmetic local Langlands correspondence, there is a conjecture that was recently (in this decade) formulated by Fargues. I can't even concisely state the conjecture so I will ...
user avatar
18 votes
1 answer
2k views

Conjecture: The number of points modulo $p$ of certain elliptic curve is $p$ or $p+2$ for $p$ of form $p=27a^2+27a+7$

Numerical evidence suggests a conjecture that the number of points of certain elliptic curve over $\mathbb{F}_p$ is either $p$ or $p+2$ for $p$ of certain form. Let $p$ be prime of the form $p=27a^2+...
joro's user avatar
  • 25.4k
12 votes
2 answers
556 views

Sylvester–Gallai theorem with circle version, plane version and curve version?

The Sylvester–Gallai theorem in geometry states that, given a finite number of points in the Euclidean plane, either All the points are collinear; or There is a line which contains exactly two of the ...
Cố Gắng Lên's user avatar
18 votes
1 answer
1k views

Which motivic cohomology groups of complex numbers are non-torsion?

I would like to know which motivic cohomology groups of complex numbers are non-zero and ("better") non-torsion, i.e., for which $(i,j)$ the $i$th cohomology of the complex ${\mathbb{Q}}(j)$ over $\...
Mikhail Bondarko's user avatar
4 votes
1 answer
684 views

A problem of four curves

This is a generalization of my previous question, a problem of a cubic and six conics. Let a curve $(K)$ of degree $m$ and three curves $(C_i)$ of degree $n$, for $i=1,2,3$. Let $(C_1)$ meets $(K)$ ...
Oai Thanh Đào's user avatar
15 votes
1 answer
732 views

A cubic and six conics problem

I am an electrical engineer system. I live in Viet Nam. I am not a Mathematician. I construct and found a problem as follows: Let a cubic, and five conics $(C_1)$, $(C_2)$, $(C_3)$, $(C_4)$, $(C_5)$. ...
Oai Thanh Đào's user avatar
4 votes
0 answers
416 views

What is behind the Hodge conjecture? [duplicate]

My question is quite naive, and my knowledge limited on the subject. I heard lot of talks about Hodge conjecture. I wanted to ask about an intuitive way to figure out why we should care about Hodge ...
lilia's user avatar
  • 235
5 votes
1 answer
365 views

A conjecture associated with n-gon cut curve of degree m

This conjecture is a generalization of A theorem for cubic-A generalization of Carnot theorem, in MSE question. I'm an electrical engineer, I am not a mathematician. I don't know how to prove this ...
Oai Thanh Đào's user avatar
4 votes
1 answer
578 views

A conjecture like Cayley–Bacharach theorem

Let six points $A, A', B, B', C, C'$ lie on a conic and a cubic. Let a conic through $B, B', C, C'$ and meets the cubic again at $A_1, A_2$. Let a conic through $C, C', A, A'$ and meets the cubic ...
Oai Thanh Đào's user avatar
8 votes
1 answer
380 views

Is the Tate conjecture known for etale covers of products of curves

Let $X$ be a (smooth projective geometrically connected) surface over a finitely generated field $k$. The Tate conjecture predicts that, for $l$ a prime number invertible in $k$, the Chern class map ...
Fudly San's user avatar