i) Instead of x￣n+ y￣n = z￣n ,we use as the general equation of Fermat's Last Theorem (FLT),where a and b are two arbitrary natural numbers .By means of binomial expansion ,(0.1) an be written as Because a￣...i) Instead of x￣n+ y￣n = z￣n ,we use as the general equation of Fermat's Last Theorem (FLT),where a and b are two arbitrary natural numbers .By means of binomial expansion ,(0.1) an be written as Because a￣r-(-b)￣r always contains a +b as its factor ,(0.2) can be written as where φ_r =[a￣r-(-b)￣r]/ (a+b ) are integers for r=1 . 2, 3. ...n (ii) Lets be a factor of a+b and let (a +b) = se. We can use x= sy to transform (0.3 ) to the following (0.4)(iii ) Dividing (0.4) by s￣2 we have On the left side of (0.5) there is a polynomial of y with integer coefficient and on the right side there is a constant cφ/s .If cφ/s is not an integer ,then we cannot find an integer y to satisfy (0.5), and then FLT is true for this case. If cφ_n/s is an integer ,we may change a and c such the cφ_n/s≠an integer .展开更多
Let D be a tame central division algebra over a Henselian valued field E,D be the residue division algebra of D,E be the residue field of E,and n be a positive integer.We prove that M_(n)(D)has a strictly maximal subf...Let D be a tame central division algebra over a Henselian valued field E,D be the residue division algebra of D,E be the residue field of E,and n be a positive integer.We prove that M_(n)(D)has a strictly maximal subfield which is Galois(resp.,abelian)over E if and only if M_(n)(D)has a strictly maximal subfield K which is Galois(resp.,abelian)and tame over E withГ_(K)■Г_(D),whereГ_(K)andГ_(D)are the value groups of K and D,respectively.This partially generalizes the result proved by Hanke et al.in 2016 for the case n=1.展开更多
In this paper, we construct some cyclic division algebras （K/F,σ,γ）. We obtain a necessary and sufficient condition of a non-norm elementγ provided that F = Q and K is a subfield of a cyclotomic field Q（ζpu）, ...In this paper, we construct some cyclic division algebras （K/F,σ,γ）. We obtain a necessary and sufficient condition of a non-norm elementγ provided that F = Q and K is a subfield of a cyclotomic field Q（ζpu）, where p is a prime and ζpu is a pu th primitive root of unity. As an application for space time block codes, we also construct cyclic division algebras （K/F,σ, γ）, where F = Q（i）, i = √-1, K is a subfield of Q（ζ4pu） or Q（ζ4pu1 pu2）, and γ = 1＋i. Moreover, we describe all cyclic division algebras （K/F, σ, γ） such that F = Q（i）, K is a subfield of L = Q（ζ4pu1, pu2） and γ= 1 ＋i, where [K： F] = φ（pu1 pu2）/d, d = 2 or 4, φ is the Euler totient function, and p1,p2 ≤ 100 are distinct odd primes.展开更多
In this note we first introduce the finite weak Herstein condition, which is a property that holds for every finite field. For a field F satisfying the finite weak Herstein condition, we then characterize whether all ...In this note we first introduce the finite weak Herstein condition, which is a property that holds for every finite field. For a field F satisfying the finite weak Herstein condition, we then characterize whether all the finite-dimensional division F-algebras are commutative. This gives an alternate proof of Wedderburn＇s Theorem.展开更多
Is a semiprimary right self-injective ring a quasi-Frobenius ring？ Almost half century has passed since Faith raised this problem. He first conjectured “No” in his book Algebra II. Ring Theory in 1976, but changing...Is a semiprimary right self-injective ring a quasi-Frobenius ring？ Almost half century has passed since Faith raised this problem. He first conjectured “No” in his book Algebra II. Ring Theory in 1976, but changing his mind, he conjectured “Yes” in his article “When self-injective rings are QF： a report on a problem” in 1990. In this paper, we describe recent studies of this problem based on authors works and raise related problems.展开更多
文摘i) Instead of x￣n+ y￣n = z￣n ,we use as the general equation of Fermat's Last Theorem (FLT),where a and b are two arbitrary natural numbers .By means of binomial expansion ,(0.1) an be written as Because a￣r-(-b)￣r always contains a +b as its factor ,(0.2) can be written as where φ_r =[a￣r-(-b)￣r]/ (a+b ) are integers for r=1 . 2, 3. ...n (ii) Lets be a factor of a+b and let (a +b) = se. We can use x= sy to transform (0.3 ) to the following (0.4)(iii ) Dividing (0.4) by s￣2 we have On the left side of (0.5) there is a polynomial of y with integer coefficient and on the right side there is a constant cφ/s .If cφ/s is not an integer ,then we cannot find an integer y to satisfy (0.5), and then FLT is true for this case. If cφ_n/s is an integer ,we may change a and c such the cφ_n/s≠an integer .
文摘Let D be a tame central division algebra over a Henselian valued field E,D be the residue division algebra of D,E be the residue field of E,and n be a positive integer.We prove that M_(n)(D)has a strictly maximal subfield which is Galois(resp.,abelian)over E if and only if M_(n)(D)has a strictly maximal subfield K which is Galois(resp.,abelian)and tame over E withГ_(K)■Г_(D),whereГ_(K)andГ_(D)are the value groups of K and D,respectively.This partially generalizes the result proved by Hanke et al.in 2016 for the case n=1.
文摘In this paper, we construct some cyclic division algebras （K/F,σ,γ）. We obtain a necessary and sufficient condition of a non-norm elementγ provided that F = Q and K is a subfield of a cyclotomic field Q（ζpu）, where p is a prime and ζpu is a pu th primitive root of unity. As an application for space time block codes, we also construct cyclic division algebras （K/F,σ, γ）, where F = Q（i）, i = √-1, K is a subfield of Q（ζ4pu） or Q（ζ4pu1 pu2）, and γ = 1＋i. Moreover, we describe all cyclic division algebras （K/F, σ, γ） such that F = Q（i）, K is a subfield of L = Q（ζ4pu1, pu2） and γ= 1 ＋i, where [K： F] = φ（pu1 pu2）/d, d = 2 or 4, φ is the Euler totient function, and p1,p2 ≤ 100 are distinct odd primes.
文摘In this note we first introduce the finite weak Herstein condition, which is a property that holds for every finite field. For a field F satisfying the finite weak Herstein condition, we then characterize whether all the finite-dimensional division F-algebras are commutative. This gives an alternate proof of Wedderburn＇s Theorem.
文摘Is a semiprimary right self-injective ring a quasi-Frobenius ring？ Almost half century has passed since Faith raised this problem. He first conjectured “No” in his book Algebra II. Ring Theory in 1976, but changing his mind, he conjectured “Yes” in his article “When self-injective rings are QF： a report on a problem” in 1990. In this paper, we describe recent studies of this problem based on authors works and raise related problems.
