3,377 reputation
1837
bio website jakitoimgeisterhaus.blogspot.…
location Munich, Germany
age 38
visits member for 3 years, 6 months
seen 12 hours ago

My past research interests included differential algebraic equations, nonlinear analysis and relations between symmetries and structural properties.

I recently investigated hierarchical structures, starting from group cohomology, continuing with semi-group theory and ending with lattices and universal algebra.


Nov
3
asked Example of a commutative ring which is not a subring of a commutative ring where every non-invertible element is a zero-divisor
Nov
1
asked Which associative and commutative operations are defined for any commutative ring?
Oct
31
answered Can the b-adic representation of rational numbers (by quote notation) be extended to non-terminating expansions?
Oct
30
asked Can the b-adic representation of rational numbers (by quote notation) be extended to non-terminating expansions?
Oct
6
answered Are higher order logics substantially stronger than second order
Oct
4
asked Is multiplication in mixed radix numeral systems complicated?
Aug
18
answered How much maths can we do in NF(U)?
Aug
16
answered Why learn to solve differential equations when computers can do it?
Aug
15
answered Can Goodstein's theorem be expressed as an axiom or axiom scheme in PA?
Aug
15
answered Which natural number predicates can be defined in Robinson arithmetic?
Jul
20
answered Why are box topology and product topology different on infinite products of topological spaces?
Jul
12
asked Which natural number predicates can be defined in Robinson arithmetic?
Jul
10
asked Can a biased physical random source be post-processed to control the bias?
Jul
7
asked Which biased random sources can be obtained from an unbiased one?
Jun
25
answered Are these two equivalences really as “immediate” as Jean-Yves Girard claims?
Jun
22
asked Are these two equivalences really as “immediate” as Jean-Yves Girard claims?
Jun
9
answered Type theory as foundations
Jun
9
answered Is there a (foundational) type theory with the features I'm looking for?
Jun
7
answered Is there a (foundational) type theory with the features I'm looking for?
Jun
1
answered How do I turn a “broken” plot into a smooth curve