Existence of maps on $\mathbb{N} \cup \{0\}$ satisfying $\phi(ab)=\phi(a)+\phi(b)$
123891
There are finitely many maps on nonnegative integers satisfying $\phi(ab)=\phi(a)+\phi(b)$
109498
Linear maps $f: M_n \longrightarrow \mathbb{R}$ such that $f(AB) = f(BA)$
140212
Prove that there exists a unique linear map that extends the map from a basis
55393
Existence of a group isomorphism between $(\mathbb K,+)$ and $(\mathbb K^\times,\cdot)$
113892
Show $A \in \cal F$ exists, such that $\mathbb P(A)=1$ and $\mathbb Q(A)=0$.
52323
Maps - question about $f(A \cup B)=f(A) \cup f(B)$ and $ f(A \cap B)=f(A) \cap f(B)$
71108
Is there an integer $N>0$ such that $\varphi(n) = N$ has infinitely many solutions?
103397
Homeomorphisms between infinite-dimensional Banach spaces and their spheres
142174
Nonexistence of an injective $C^1$ map between $\mathbb R^2$ and $\mathbb R$
149661
For $n=pq$, show that there exist $\alpha, \beta \in Z_n^*$ such that $\alpha, \beta \notin (Z_n^*)^2$ and $\alpha \cdot \beta \notin (Z_n^*)^2$.
116527
Validating a proof for necessary and sufficient conditions on sets A & B such that $P(A) \cup P(B) = P(A\cup B)$
52135
Show that $A \setminus ( B \setminus C ) \equiv ( A \setminus B) \cup ( A \cap C )$
88153
Finding all inner products on $\mathbb{R}^2$ for which a given linear map is orthogonal
90649
Consider $f(x)=mx$ and $g(x) =bx$ in which $m>0$ and $b>0$. Does there exist any homeomorphism $h$ such that $h \circ f$ = $g \circ h$
7890
Prove the map $\Phi:G\to\operatorname{Aut}G$ with $g\mapsto (x\mapsto g^{-1}xg)$ is an homomorphism.
146812
Explicit construction for unitary extensions of completely positive and trace preserving (CPTP) maps?
37841
Product of quotient maps and quotient space that is not Hausdorff