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  1. Groups, Fields, and Galois: Part 1 | UCLA Extension

    Dr. Michael Miller, a retired researcher at RAND, has been teaching upper level undergraduate/graduate level math courses for fun at UCLA Extension for over 50 years. This fall he'll be introducing the areas of groups, fields, and Galois theory from abstract algebra to those interested in abstract math: Groups, Fields, and Galois: Part 1. His intention is to do a follow-on class on Galois theory in the Winter which will use this class as a foundation. If you're in the Los Angeles area his […]

    boffosocko.com/2026/08/13/grou

  2. MVspa_ Stochastic processes
    Стохастические процессы, Випадкові процеси
    #Stochastic processes
    #Стохастическиепроцессы, #Випадковіпроцеси
    t.me/scilib_yura15cbx/230

    MVsa Statistics and applications
    Статистика та додатки, Статистика и приложения
    #Statistics
    t.me/scilib_yura15cbx/229

    EM_ Mechanics of elastic materials
    Механіка пружних матеріалів, Механика упругих материалов
    t.me/scilib_yura15cbx/228

    MPd_ Dynamical systems
    Динамические системы, Динамічні системи
    #Dynamical systems
    t.me/scilib_yura15cbx/227

    MNw_ Wavelets, signal processing
    Вейвлети, обробка сигналів, Вейвлеты, обработка сигналов
    #Wavelets, #signal processing
    t.me/scilib_yura15cbx/226

    MNs_ Simulations of physics
    Физические симуляции
    t.me/scilib_yura15cbx/225

    MNl_ Numerical linear algebra
    Числова лінійна алгебра, Численная линейная алгебра
    t.me/scilib_yura15cbx/224

    MNf_ Finite elements
    Конечные элементы, Скінченні елементи
    t.me/scilib_yura15cbx/223

    MNd_ Numerical calculus
    t.me/scilib_yura15cbx/222

    MDgt_ General topology
    #topology
    Общая топология, Загальна топологія
    t.me/scilib_yura15cbx/221

    MDdg_ Differential geometry
    Диференціальна геометрія, Дифференциальная геометрия
    t.me/scilib_yura15cbx/220

    MDat_ Algebraic and differential topology
    Алгебраическая и дифференциальная топология, Алгебраїчна та диференціальна топологія
    t.me/scilib_yura15cbx/219

    MCv_ Variational calculus
    Варіаційне числення, Вариационное исчисление
    t.me/scilib_yura15cbx/218

    MCta_ Tensor calculus, forms
    Тензорное исчисление, формы, Тензорне числення, форми
    t.me/scilib_yura15cbx/217

    MCsf_ Special functions
    Спеціальні функції, Специальные функции
    t.me/scilib_yura15cbx/216

    MCf_ Functional analysis
    Функциональный анализ, Функціональний аналіз
    t.me/scilib_yura15cbx/215

    MCet_ Elementary calculus textbooks
    Підручники з елементарного числення, Учебники по элементарному исчислению
    t.me/scilib_yura15cbx/214

    MCde_ Differential equations
    Дифференциальные уравнения, Диференціальні рівняння
    #Differential equations
    t.me/scilib_yura15cbx/213

    MCcf_ Continued fractions
    Суцільні дроби, Непрерывные дроби
    t.me/scilib_yura15cbx/212

    MCc_ Complex variable
    Комплексная переменная, Комплексна змінна
    t.me/scilib_yura15cbx/211

    MCat_ Advanced calculus
    t.me/scilib_yura15cbx/210

    Asymptotics, perturbations
    Асимптотика, збурення,
    Асимптотика, возмущения
    #Asymptotics, #perturbations
    #Асимптотика, #збурення,
    #Асимптотика, #возмущения
    t.me/scilib_yura15cbx/209

    Group theory, Теория групп, Теорія груп
    #Group theory, #Теориягрупп, #Теоріягруп
    t.me/scilib_yura15cbx/208

    Algebra textbooks,
    Підручники з алгебри,
    Учебники по алгебре
    t.me/scilib_yura15cbx/207

    Set theory,
    Теория множеств, Теорія множин
    #Set theory,
    #Теория множеств,
    t.me/scilib_yura15cbx/206

    Representation theory
    Теорія репрезентації, Теория представлений
    t.me/scilib_yura15cbx/205

    Quantum groups
    #Quantum groups
    Квантовые группы, Квантові групи
    t.me/scilib_yura15cbx/204

    Mathematical logic
    #Mathematical logic
    Математична логіка, Математическая логика
    t.me/scilib_yura15cbx/203

    Linear algebra
    #Linear algebra
    Линейная алгебра, Лінійна алгебра
    t.me/scilib_yura15cbx/202

    Homology, Гомологія, Гомология
    #Homology, #Гомологія, #Гомология
    t.me/scilib_yura15cbx/201

    Algebraic geometry
    Алгебраическая геометрия, Алгебраїчна геометрія
    t.me/scilib_yura15cbx/200

    Algebraic geometry
    #Algebraic geometry
    Алгебраическая геометрия, Алгебраїчна геометрія
    t.me/scilib_yura15cbx/200

    Finite groups
    Скінченні групи, Конечные группы
    t.me/scilib_yura15cbx/199

    Differential algebra
    #Differential algebra
    Дифференциальная алгебра, Диференціальна алгебра
    t.me/scilib_yura15cbx/198

    Category theory
    Теорія категорій, Теория категорий

  3. MVspa_ Stochastic processes
    Стохастические процессы, Випадкові процеси
    #Stochastic processes
    #Стохастическиепроцессы, #Випадковіпроцеси
    t.me/scilib_yura15cbx/230

    MVsa Statistics and applications
    Статистика та додатки, Статистика и приложения
    #Statistics
    t.me/scilib_yura15cbx/229

    EM_ Mechanics of elastic materials
    Механіка пружних матеріалів, Механика упругих материалов
    t.me/scilib_yura15cbx/228

    MPd_ Dynamical systems
    Динамические системы, Динамічні системи
    #Dynamical systems
    t.me/scilib_yura15cbx/227

    MNw_ Wavelets, signal processing
    Вейвлети, обробка сигналів, Вейвлеты, обработка сигналов
    #Wavelets, #signal processing
    t.me/scilib_yura15cbx/226

    MNs_ Simulations of physics
    Физические симуляции
    t.me/scilib_yura15cbx/225

    MNl_ Numerical linear algebra
    Числова лінійна алгебра, Численная линейная алгебра
    t.me/scilib_yura15cbx/224

    MNf_ Finite elements
    Конечные элементы, Скінченні елементи
    t.me/scilib_yura15cbx/223

    MNd_ Numerical calculus
    t.me/scilib_yura15cbx/222

    MDgt_ General topology
    #topology
    Общая топология, Загальна топологія
    t.me/scilib_yura15cbx/221

    MDdg_ Differential geometry
    Диференціальна геометрія, Дифференциальная геометрия
    t.me/scilib_yura15cbx/220

    MDat_ Algebraic and differential topology
    Алгебраическая и дифференциальная топология, Алгебраїчна та диференціальна топологія
    t.me/scilib_yura15cbx/219

    MCv_ Variational calculus
    Варіаційне числення, Вариационное исчисление
    t.me/scilib_yura15cbx/218

    MCta_ Tensor calculus, forms
    Тензорное исчисление, формы, Тензорне числення, форми
    t.me/scilib_yura15cbx/217

    MCsf_ Special functions
    Спеціальні функції, Специальные функции
    t.me/scilib_yura15cbx/216

    MCf_ Functional analysis
    Функциональный анализ, Функціональний аналіз
    t.me/scilib_yura15cbx/215

    MCet_ Elementary calculus textbooks
    Підручники з елементарного числення, Учебники по элементарному исчислению
    t.me/scilib_yura15cbx/214

    MCde_ Differential equations
    Дифференциальные уравнения, Диференціальні рівняння
    #Differential equations
    t.me/scilib_yura15cbx/213

    MCcf_ Continued fractions
    Суцільні дроби, Непрерывные дроби
    t.me/scilib_yura15cbx/212

    MCc_ Complex variable
    Комплексная переменная, Комплексна змінна
    t.me/scilib_yura15cbx/211

    MCat_ Advanced calculus
    t.me/scilib_yura15cbx/210

    Asymptotics, perturbations
    Асимптотика, збурення,
    Асимптотика, возмущения
    #Asymptotics, #perturbations
    #Асимптотика, #збурення,
    #Асимптотика, #возмущения
    t.me/scilib_yura15cbx/209

    Group theory, Теория групп, Теорія груп
    #Group theory, #Теориягрупп, #Теоріягруп
    t.me/scilib_yura15cbx/208

    Algebra textbooks,
    Підручники з алгебри,
    Учебники по алгебре
    t.me/scilib_yura15cbx/207

    Set theory,
    Теория множеств, Теорія множин
    #Set theory,
    #Теория множеств,
    t.me/scilib_yura15cbx/206

    Representation theory
    Теорія репрезентації, Теория представлений
    t.me/scilib_yura15cbx/205

    Quantum groups
    #Quantum groups
    Квантовые группы, Квантові групи
    t.me/scilib_yura15cbx/204

    Mathematical logic
    #Mathematical logic
    Математична логіка, Математическая логика
    t.me/scilib_yura15cbx/203

    Linear algebra
    #Linear algebra
    Линейная алгебра, Лінійна алгебра
    t.me/scilib_yura15cbx/202

    Homology, Гомологія, Гомология
    #Homology, #Гомологія, #Гомология
    t.me/scilib_yura15cbx/201

    Algebraic geometry
    Алгебраическая геометрия, Алгебраїчна геометрія
    t.me/scilib_yura15cbx/200

    Algebraic geometry
    #Algebraic geometry
    Алгебраическая геометрия, Алгебраїчна геометрія
    t.me/scilib_yura15cbx/200

    Finite groups
    Скінченні групи, Конечные группы
    t.me/scilib_yura15cbx/199

    Differential algebra
    #Differential algebra
    Дифференциальная алгебра, Диференціальна алгебра
    t.me/scilib_yura15cbx/198

    Category theory
    Теорія категорій, Теория категорий

  4. MVspa_ Stochastic processes
    Стохастические процессы, Випадкові процеси
    #Stochastic processes
    #Стохастическиепроцессы, #Випадковіпроцеси
    t.me/scilib_yura15cbx/230

    MVsa Statistics and applications
    Статистика та додатки, Статистика и приложения
    #Statistics
    t.me/scilib_yura15cbx/229

    EM_ Mechanics of elastic materials
    Механіка пружних матеріалів, Механика упругих материалов
    t.me/scilib_yura15cbx/228

    MPd_ Dynamical systems
    Динамические системы, Динамічні системи
    #Dynamical systems
    t.me/scilib_yura15cbx/227

    MNw_ Wavelets, signal processing
    Вейвлети, обробка сигналів, Вейвлеты, обработка сигналов
    #Wavelets, #signal processing
    t.me/scilib_yura15cbx/226

    MNs_ Simulations of physics
    Физические симуляции
    t.me/scilib_yura15cbx/225

    MNl_ Numerical linear algebra
    Числова лінійна алгебра, Численная линейная алгебра
    t.me/scilib_yura15cbx/224

    MNf_ Finite elements
    Конечные элементы, Скінченні елементи
    t.me/scilib_yura15cbx/223

    MNd_ Numerical calculus
    t.me/scilib_yura15cbx/222

    MDgt_ General topology
    #topology
    Общая топология, Загальна топологія
    t.me/scilib_yura15cbx/221

    MDdg_ Differential geometry
    Диференціальна геометрія, Дифференциальная геометрия
    t.me/scilib_yura15cbx/220

    MDat_ Algebraic and differential topology
    Алгебраическая и дифференциальная топология, Алгебраїчна та диференціальна топологія
    t.me/scilib_yura15cbx/219

    MCv_ Variational calculus
    Варіаційне числення, Вариационное исчисление
    t.me/scilib_yura15cbx/218

    MCta_ Tensor calculus, forms
    Тензорное исчисление, формы, Тензорне числення, форми
    t.me/scilib_yura15cbx/217

    MCsf_ Special functions
    Спеціальні функції, Специальные функции
    t.me/scilib_yura15cbx/216

    MCf_ Functional analysis
    Функциональный анализ, Функціональний аналіз
    t.me/scilib_yura15cbx/215

    MCet_ Elementary calculus textbooks
    Підручники з елементарного числення, Учебники по элементарному исчислению
    t.me/scilib_yura15cbx/214

    MCde_ Differential equations
    Дифференциальные уравнения, Диференціальні рівняння
    #Differential equations
    t.me/scilib_yura15cbx/213

    MCcf_ Continued fractions
    Суцільні дроби, Непрерывные дроби
    t.me/scilib_yura15cbx/212

    MCc_ Complex variable
    Комплексная переменная, Комплексна змінна
    t.me/scilib_yura15cbx/211

    MCat_ Advanced calculus
    t.me/scilib_yura15cbx/210

    Asymptotics, perturbations
    Асимптотика, збурення,
    Асимптотика, возмущения
    #Asymptotics, #perturbations
    #Асимптотика, #збурення,
    #Асимптотика, #возмущения
    t.me/scilib_yura15cbx/209

    Group theory, Теория групп, Теорія груп
    #Group theory, #Теориягрупп, #Теоріягруп
    t.me/scilib_yura15cbx/208

    Algebra textbooks,
    Підручники з алгебри,
    Учебники по алгебре
    t.me/scilib_yura15cbx/207

    Set theory,
    Теория множеств, Теорія множин
    #Set theory,
    #Теория множеств,
    t.me/scilib_yura15cbx/206

    Representation theory
    Теорія репрезентації, Теория представлений
    t.me/scilib_yura15cbx/205

    Quantum groups
    #Quantum groups
    Квантовые группы, Квантові групи
    t.me/scilib_yura15cbx/204

    Mathematical logic
    #Mathematical logic
    Математична логіка, Математическая логика
    t.me/scilib_yura15cbx/203

    Linear algebra
    #Linear algebra
    Линейная алгебра, Лінійна алгебра
    t.me/scilib_yura15cbx/202

    Homology, Гомологія, Гомология
    #Homology, #Гомологія, #Гомология
    t.me/scilib_yura15cbx/201

    Algebraic geometry
    Алгебраическая геометрия, Алгебраїчна геометрія
    t.me/scilib_yura15cbx/200

    Algebraic geometry
    #Algebraic geometry
    Алгебраическая геометрия, Алгебраїчна геометрія
    t.me/scilib_yura15cbx/200

    Finite groups
    Скінченні групи, Конечные группы
    t.me/scilib_yura15cbx/199

    Differential algebra
    #Differential algebra
    Дифференциальная алгебра, Диференціальна алгебра
    t.me/scilib_yura15cbx/198

    Category theory
    Теорія категорій, Теория категорий

  5. MVspa_ Stochastic processes
    Стохастические процессы, Випадкові процеси
    #Stochastic processes
    #Стохастическиепроцессы, #Випадковіпроцеси
    t.me/scilib_yura15cbx/230

    MVsa Statistics and applications
    Статистика та додатки, Статистика и приложения
    #Statistics
    t.me/scilib_yura15cbx/229

    EM_ Mechanics of elastic materials
    Механіка пружних матеріалів, Механика упругих материалов
    t.me/scilib_yura15cbx/228

    MPd_ Dynamical systems
    Динамические системы, Динамічні системи
    #Dynamical systems
    t.me/scilib_yura15cbx/227

    MNw_ Wavelets, signal processing
    Вейвлети, обробка сигналів, Вейвлеты, обработка сигналов
    #Wavelets, #signal processing
    t.me/scilib_yura15cbx/226

    MNs_ Simulations of physics
    Физические симуляции
    t.me/scilib_yura15cbx/225

    MNl_ Numerical linear algebra
    Числова лінійна алгебра, Численная линейная алгебра
    t.me/scilib_yura15cbx/224

    MNf_ Finite elements
    Конечные элементы, Скінченні елементи
    t.me/scilib_yura15cbx/223

    MNd_ Numerical calculus
    t.me/scilib_yura15cbx/222

    MDgt_ General topology
    #topology
    Общая топология, Загальна топологія
    t.me/scilib_yura15cbx/221

    MDdg_ Differential geometry
    Диференціальна геометрія, Дифференциальная геометрия
    t.me/scilib_yura15cbx/220

    MDat_ Algebraic and differential topology
    Алгебраическая и дифференциальная топология, Алгебраїчна та диференціальна топологія
    t.me/scilib_yura15cbx/219

    MCv_ Variational calculus
    Варіаційне числення, Вариационное исчисление
    t.me/scilib_yura15cbx/218

    MCta_ Tensor calculus, forms
    Тензорное исчисление, формы, Тензорне числення, форми
    t.me/scilib_yura15cbx/217

    MCsf_ Special functions
    Спеціальні функції, Специальные функции
    t.me/scilib_yura15cbx/216

    MCf_ Functional analysis
    Функциональный анализ, Функціональний аналіз
    t.me/scilib_yura15cbx/215

    MCet_ Elementary calculus textbooks
    Підручники з елементарного числення, Учебники по элементарному исчислению
    t.me/scilib_yura15cbx/214

    MCde_ Differential equations
    Дифференциальные уравнения, Диференціальні рівняння
    #Differential equations
    t.me/scilib_yura15cbx/213

    MCcf_ Continued fractions
    Суцільні дроби, Непрерывные дроби
    t.me/scilib_yura15cbx/212

    MCc_ Complex variable
    Комплексная переменная, Комплексна змінна
    t.me/scilib_yura15cbx/211

    MCat_ Advanced calculus
    t.me/scilib_yura15cbx/210

    Asymptotics, perturbations
    Асимптотика, збурення,
    Асимптотика, возмущения
    #Asymptotics, #perturbations
    #Асимптотика, #збурення,
    #Асимптотика, #возмущения
    t.me/scilib_yura15cbx/209

    Group theory, Теория групп, Теорія груп
    #Group theory, #Теориягрупп, #Теоріягруп
    t.me/scilib_yura15cbx/208

    Algebra textbooks,
    Підручники з алгебри,
    Учебники по алгебре
    t.me/scilib_yura15cbx/207

    Set theory,
    Теория множеств, Теорія множин
    #Set theory,
    #Теория множеств,
    t.me/scilib_yura15cbx/206

    Representation theory
    Теорія репрезентації, Теория представлений
    t.me/scilib_yura15cbx/205

    Quantum groups
    #Quantum groups
    Квантовые группы, Квантові групи
    t.me/scilib_yura15cbx/204

    Mathematical logic
    #Mathematical logic
    Математична логіка, Математическая логика
    t.me/scilib_yura15cbx/203

    Linear algebra
    #Linear algebra
    Линейная алгебра, Лінійна алгебра
    t.me/scilib_yura15cbx/202

    Homology, Гомологія, Гомология
    #Homology, #Гомологія, #Гомология
    t.me/scilib_yura15cbx/201

    Algebraic geometry
    Алгебраическая геометрия, Алгебраїчна геометрія
    t.me/scilib_yura15cbx/200

    Algebraic geometry
    #Algebraic geometry
    Алгебраическая геометрия, Алгебраїчна геометрія
    t.me/scilib_yura15cbx/200

    Finite groups
    Скінченні групи, Конечные группы
    t.me/scilib_yura15cbx/199

    Differential algebra
    #Differential algebra
    Дифференциальная алгебра, Диференціальна алгебра
    t.me/scilib_yura15cbx/198

    Category theory
    Теорія категорій, Теория категорий

  6. #Mathematics #GroupTheory #Algebra #TheoreticalComputerScience

    In my study (a while ago) I learned about Σ Algebras (theoretical computer science).
    Then later, I learnt in math there are σ Algebras, which seems sort of the same thing.
    Today I'm curious about group theory, and groups are also sort of the same thing.

    Can anyone tell me what's the difference? Between Σ Algebras, σ Algebras, and groups?

  7. #Mathematics #GroupTheory #Algebra #TheoreticalComputerScience

    In my study (a while ago) I learned about Σ Algebras (theoretical computer science).
    Then later, I learnt in math there are σ Algebras, which seems sort of the same thing.
    Today I'm curious about group theory, and groups are also sort of the same thing.

    Can anyone tell me what's the difference? Between Σ Algebras, σ Algebras, and groups?

  8. Riffs and Rotes • Happy New Year 2026
    inquiryintoinquiry.com/2026/01

    There's a deep mathematical significance I see in the following structures, and I'm hoping one day to find a way to explain all the things I see there. Meanwhile, you may take them as an amusing diversion in recreational maths.

    \( \text{Let} ~ p_n = \text{the} ~ n^\text{th} ~ \text{prime}. \)

    \( \begin{array}{llcl}
    \text{Then} & 2026 & = & 2 \cdot 1013
    \\
    && = & p_1 p_{170}
    \\
    && = & p_1 p_{2 \cdot 5 \cdot 17}
    \\
    && = & p_1 p_{p_1 p_3 p_7}
    \\
    && = & p_1 p_{p_1 p_{p_2} p_{p_4}}
    \\
    && = & p_1 p_{p_1 p_{p_{p_1}} p_{p_{{p_1}^{p_1}}}}
    \end{array} \)

    No information is lost by dropping the terminal 1s. Thus we may write the following form.

    \[ 2026 = p p_{p p_{p_p} p_{p_{p^p}}} \]

    The article linked below tells how forms of that order correspond to a family of digraphs called “riffs” and a family of graphs called “rotes”.

    The riff and rote for 2026 are shown in the next two Figures.

    Riff 2026
    inquiryintoinquiry.com/wp-cont

    Rote 2026
    inquiryintoinquiry.com/wp-cont

    Reference —

    Riffs and Rotes
    oeis.org/wiki/Riffs_and_Rotes

    cc: academia.edu/community/VBA6Qz
    cc: researchgate.net/post/Riffs_an

    #Arithmetic #Combinatorics #Computation #Factorization #GraphTheory #GroupTheory
    #Logic #Mathematics #NumberTheory #Primes #Recursion #Representation #RiffsAndRotes

  9. Riffs and Rotes • Happy New Year 2026
    inquiryintoinquiry.com/2026/01

    There's a deep mathematical significance I see in the following structures, and I'm hoping one day to find a way to explain all the things I see there. Meanwhile, you may take them as an amusing diversion in recreational maths.

    \( \text{Let} ~ p_n = \text{the} ~ n^\text{th} ~ \text{prime}. \)

    \( \begin{array}{llcl}
    \text{Then} & 2026 & = & 2 \cdot 1013
    \\
    && = & p_1 p_{170}
    \\
    && = & p_1 p_{2 \cdot 5 \cdot 17}
    \\
    && = & p_1 p_{p_1 p_3 p_7}
    \\
    && = & p_1 p_{p_1 p_{p_2} p_{p_4}}
    \\
    && = & p_1 p_{p_1 p_{p_{p_1}} p_{p_{{p_1}^{p_1}}}}
    \end{array} \)

    No information is lost by dropping the terminal 1s. Thus we may write the following form.

    \[ 2026 = p p_{p p_{p_p} p_{p_{p^p}}} \]

    The article linked below tells how forms of that order correspond to a family of digraphs called “riffs” and a family of graphs called “rotes”.

    The riff and rote for 2026 are shown in the next two Figures.

    Riff 2026
    inquiryintoinquiry.com/wp-cont

    Rote 2026
    inquiryintoinquiry.com/wp-cont

    Reference —

    Riffs and Rotes
    oeis.org/wiki/Riffs_and_Rotes

    cc: academia.edu/community/VBA6Qz
    cc: researchgate.net/post/Riffs_an

    #Arithmetic #Combinatorics #Computation #Factorization #GraphTheory #GroupTheory
    #Logic #Mathematics #NumberTheory #Primes #Recursion #Representation #RiffsAndRotes

  10. A section of a group G is a quotient of a subgroup, viz. K normal in H subgroup of G, the section is H/K.

    Does anyone know if there is a more-or-less standard terminology not just for the section-up-to-isomorphism-of-the-group-H/K, but for the "instantiated" or maybe "concrete" section, e.g. the pair (K,H)?

    #Math #Algebra #GroupTheory

  11. A section of a group G is a quotient of a subgroup, viz. K normal in H subgroup of G, the section is H/K.

    Does anyone know if there is a more-or-less standard terminology not just for the section-up-to-isomorphism-of-the-group-H/K, but for the "instantiated" or maybe "concrete" section, e.g. the pair (K,H)?

    #Math #Algebra #GroupTheory

  12. Quanta Magazine really has nicely in-depth yet approachable writing on #mathematics, in this case an introduction to Lie groups #GroupTheory quantamagazine.org/what-are-li

  13. Quanta Magazine really has nicely in-depth yet approachable writing on #mathematics, in this case an introduction to Lie groups #GroupTheory quantamagazine.org/what-are-li

  14. Some time ago for practicing #haskell I implemented a well know algorithm for combining multiplets github.com/mdrslmr/MultipletCo . This algorithm from #grouptheory is used in #particlephysics and other #physics topics. The code is probably pretty useless since the results are anyway textbook standards. But I found it was a nice exercise. I'm sure the code can be improved a lot easily.

  15. Why are normal subgroups called "normal?" Most subgroups are not normal, which seemingly makes the name incorrect.

    But in an Abelian group, all subgroups are normal. Abelian groups were the first groups to be studied by white European men, and they are the easiest for humans to work with.

    Therefore, normal subgroups are called normal because they are the subgroups which pose the least challenge to the incumbent power structures.

    #GroupTheory #NormalSubgroup

  16. Why are normal subgroups called "normal?" Most subgroups are not normal, which seemingly makes the name incorrect.

    But in an Abelian group, all subgroups are normal. Abelian groups were the first groups to be studied by white European men, and they are the easiest for humans to work with.

    Therefore, normal subgroups are called normal because they are the subgroups which pose the least challenge to the incumbent power structures.

    #GroupTheory #NormalSubgroup

  17. Drafted a 3rd inquiry activity for D3 and D4 play with flips and rotations.

    I am hoping it's not to dry. I'll read through it again tomorrow.

    #mtbos #dihedral #grouptheory #iteachmath

  18. Drafted a 3rd inquiry activity for D3 and D4 play with flips and rotations.

    I am hoping it's not to dry. I'll read through it again tomorrow.

    #mtbos #dihedral #grouptheory #iteachmath

  19. #DocMadhattan: The Abel Prize 2025: Masaki Kashiwara

    docmadhattan.hashnode.dev/the-

    Masaki Kashiwara wins the 2025 Abel Prize for groundbreaking work in algebraic analysis, D-modules theory, and crystal bases in representation theory

    #mathematics #physics #AbelPrize #MasakiKashiwara #grouptheory #quantumgroups

  20. Me: If you're a student in my class you will do group presentations, meaning that you will organize into a subset of the class, stand in front of the room, and talk about math to the rest of the class.

    Also me: Let's talk about group presentations, a completely abstract algebraic concept that have absolutely nothing to do with standing in front of the room talking about your work.

    Also also me: Okay, time for group presentations
    about group presentations.

    #Algebra #ITeachMath #GroupTheory #GroupPresentation

  21. Me: If you're a student in my class you will do group presentations, meaning that you will organize into a subset of the class, stand in front of the room, and talk about math to the rest of the class.

    Also me: Let's talk about group presentations, a completely abstract algebraic concept that have absolutely nothing to do with standing in front of the room talking about your work.

    Also also me: Okay, time for group presentations
    about group presentations.

    #Algebra #ITeachMath #GroupTheory #GroupPresentation

  22. New 📚 Release! Introduction to Group Theory: An Activity-Based Approach by Joe Fox #books #ebooks #math #grouptheory

    This book is an introduction to group theory suitable for an introductory course in abstract algebra. Much of the content is delegated to a series of activities that are meant to be worked through by the students with the help of the instructor.

    Find it on Leanpub!

    Link: leanpub.com/grouptheory

  23. New 📚 Release! Introduction to Group Theory: An Activity-Based Approach by Joe Fox #books #ebooks #math #grouptheory

    This book is an introduction to group theory suitable for an introductory course in abstract algebra. Much of the content is delegated to a series of activities that are meant to be worked through by the students with the help of the instructor.

    Find it on Leanpub!

    Link: leanpub.com/grouptheory

  24. Riffs and Rotes • Happy New Year 2025
    inquiryintoinquiry.com/2025/01

    \( \text{Let} ~ p_n = \text{the} ~ n^\text{th} ~ \text{prime}. \)

    \( \text{Then} ~ 2025
    = 81 \cdot 25
    = 3^4 5^2 \)

    \( = {p_2}^4 {p_3}^2
    = {p_2}^{{p_1}^{p_1}} {p_3}^{p_1}
    = {p_{p_1}}^{{p_1}^{p_1}} {p_{p_2}}^{p_1}
    = {p_{p_1}}^{{p_1}^{p_1}} {p_{p_{p_1}}}^{p_1} \)

    No information is lost by dropping the terminal 1s. Thus we may write the following form.

    \[ 2025 = {p_p}^{p^p} {p_{p_p}}^p \]

    The article linked below tells how forms of that sort correspond to a family of digraphs called “riffs” and a family of graphs called “rotes”. The riff and rote for 2025 are shown in the next two Figures.

    Riff 2025
    inquiryintoinquiry.files.wordp

    Rote 2025
    inquiryintoinquiry.files.wordp

    Reference —

    Riffs and Rotes
    oeis.org/wiki/Riffs_and_Rotes

    #Arithmetic #Combinatorics #Computation #Factorization #GraphTheory #GroupTheory
    #Logic #Mathematics #NumberTheory #Primes #Recursion #Representation #RiffsAndRotes

  25. Riffs and Rotes • Happy New Year 2025
    inquiryintoinquiry.com/2025/01

    \( \text{Let} ~ p_n = \text{the} ~ n^\text{th} ~ \text{prime}. \)

    \( \text{Then} ~ 2025
    = 81 \cdot 25
    = 3^4 5^2 \)

    \( = {p_2}^4 {p_3}^2
    = {p_2}^{{p_1}^{p_1}} {p_3}^{p_1}
    = {p_{p_1}}^{{p_1}^{p_1}} {p_{p_2}}^{p_1}
    = {p_{p_1}}^{{p_1}^{p_1}} {p_{p_{p_1}}}^{p_1} \)

    No information is lost by dropping the terminal 1s. Thus we may write the following form.

    \[ 2025 = {p_p}^{p^p} {p_{p_p}}^p \]

    The article linked below tells how forms of that sort correspond to a family of digraphs called “riffs” and a family of graphs called “rotes”. The riff and rote for 2025 are shown in the next two Figures.

    Riff 2025
    inquiryintoinquiry.files.wordp

    Rote 2025
    inquiryintoinquiry.files.wordp

    Reference —

    Riffs and Rotes
    oeis.org/wiki/Riffs_and_Rotes

    #Arithmetic #Combinatorics #Computation #Factorization #GraphTheory #GroupTheory
    #Logic #Mathematics #NumberTheory #Primes #Recursion #Representation #RiffsAndRotes

  26. A shop called "Wreath Products" that sells mathematical puzzle toys, mobiles (like for baby cribs or art)...and, sure, also decorative wreaths.

    #math #GroupTheory #algebra

  27. A shop called "Wreath Products" that sells mathematical puzzle toys, mobiles (like for baby cribs or art)...and, sure, also decorative wreaths.

    #math #GroupTheory #algebra

  28. Sat Dec 7, 2024 on zoom & in-person

    Session in memory of Richard Parker at the annual Nikolaus conference at Aachen (on group & representation theory). Main speakers:

    Gerhard Hiß
    Gabriele Nebe
    Colva Roney-Dougal

    math.rwth-aachen.de/Nikolaus20

    #Math #GroupTheory #RepresentationTheory #Algebra

  29. Sat Dec 7, 2024 on zoom & in-person

    Session in memory of Richard Parker at the annual Nikolaus conference at Aachen (on group & representation theory). Main speakers:

    Gerhard Hiß
    Gabriele Nebe
    Colva Roney-Dougal

    math.rwth-aachen.de/Nikolaus20

    #Math #GroupTheory #RepresentationTheory #Algebra

  30. @gilesgardam Adding hashtags like #GroupTheory #Algebra will help people find this post (more important on mastodon than some other microblogging platforms, b/c "there is no algorithm here", or rather, the timeline is only chronological based on follows & searches)

  31. @j2kun So addition and negation, when operating on the 𝑛-bit integers, generate the dihedral group (en.wikipedia.org/wiki/Dihedral) that expresses the symmetries of a \(2^{n-1}\)-gon.

    I didn't think of this before. 😃

    #GroupTheory

  32. Here's a tip for beginners in #AbstractAlgebra, #GroupTheory or #NumberTheory.

    Sometimes it's useful to think in terms of the divisibility ordering instead of the usual ordering where 0 ≤ 1 ≤ 2 ≤ …. Divisibility gives a partial ordering on the natural numbers where we say that n ≤ m if n divides m. Or we can extend this order to all integers, in which case n and -n become equivalent in this order because they divide each other.

    The main difference is that this isn't a total order. For example 7 doesn't divide 8 and 8 doesn't divide 7. The other difference is that while 0 is the least natural number in the usual ordering, it's the *greatest* number in the divisibility ordering, because everything divides 0!

    Thinking this way makes several definitions make more sense:

    1. The least common multiple of 12 and 10 is 60, even though 0 is also a common multiple of 12 and 10. This is because 0 is greater than 60.

    2. If an element of a group never becomes the identity when you repeatedly multiply it by itself, then we say it has order 0. This is because the order of an element is the least power of the element that equals the identity, under the divisibility ordering.

    3. Likewise we say that a ring has characteristic 0 if 1 + … + 1 is never 0. Again we can use the divisibility ordering to say that the characteristic is the least integer for which adding together that number of 1s gives 0.

    #Math #Maths #Mathematics

  33. I wrote a blog post on how to work out the injectivity radii of the unitary groups. If you like getting results in differential geometry and group theory with (mostly) just linear algebra, this one's for you! sethaxen.com/blog/2023/02/the-

    #DiffGeo #GroupTheory #LinearAlgebra

  34. Anyone know anything about solving a 7x7x7 Rubik's cube?

    I've got three centres down and I am looking for a hint (and just a hint!) if this is on the right track.

    If I should be doing something else, I would appreciate a gentle nudge in another directions.

    #RubiksCube #GroupTheory