If you have any questions, you are always welcome to contact us. We'll get back to you as soon as possible, withing 24 hours on weekdays.
Customer service
All questions about your order, return and delivery must be sent to our customer service team by e-mail at yourstore@yourdomain.com
Sale & Press
If you are interested in selling our products, need more information about our brand or wish to make a collaboration, please contact us at press@yourdomain.com
Help
If you have any questions, you are always welcome to contact us. We'll get back to you as soon as possible, withing 24 hours on weekdays.
Customer service
All questions about your order, return and delivery must be sent to our customer service team by e-mail at yourstore@yourdomain.com
Sale & Press
If you are interested in selling our products, need more information about our brand or wish to make a collaboration, please contact us at press@yourdomain.com
For a long time at least from Fermat to Minkowski the theory of quadratic forms was a part of number theory. Much of the best work of the great number theorists of the eighteenth and nineteenth century was concerned with problems about quadratic forms. On the basis of their work, Minkowski, Siegel, Hasse, Eichler and many others crea ted the impressive 'arithmetic' theory of quadratic forms, which has been the object of the wellknown books by Bachmann (1898/1923), Eichler (1952), and O'Meara (1963). Parallel to this development the ideas of abstract algebra and abstract linear algebra introduced by Dedekind, Frobenius, E. Noether and Artin led to today's structural mathematics with its emphasis on classification problems and general structure theorems. On the basis of both the number theory of quadratic forms and the ideas of modern algebra Witt opened, in 1937, a new chapter in the theory of quadratic forms. His most fruitful idea was to consider not single 'individual' quadratic forms but rather the entity of all forms over a fixed ground field and to construct from this an algebra ic object. This object the Witt ring then became the principal object of the entire theory. Thirty years later Pfister demonstrated the significance of this approach by his celebrated structure theorems.
⚠️ WARNING (California Proposition 65):
This product may contain chemicals known to the State of California to cause cancer,
birth defects, or other reproductive harm.
<div class="dynamic-checkout__content" id="dynamic-checkout-cart" data-shopify="dynamic-checkout-cart"> <shopify-accelerated-checkout-cart wallet-configs="[{"supports_subs":true,"supports_def_opts":false,"name":"shop_pay","wallet_params":{"shopId":73758048501,"merchantName":"Ergodebooks","personalized":true}},{"supports_subs":false,"supports_def_opts":false,"name":"amazon_pay","wallet_params":{"checkoutLanguage":"en_US","ledgerCurrency":"USD","placement":"Cart","sandbox":false,"merchantId":"A1G1ZY975O1T6J","productType":"PayAndShip","design":"C0002"}},{"supports_subs":true,"supports_def_opts":false,"name":"paypal","wallet_params":{"shopId":73758048501,"countryCode":"US","merchantName":"Ergodebooks","phoneRequired":true,"companyRequired":false,"shippingType":"shipping","shopifyPaymentsEnabled":true,"hasManagedSellingPlanState":false,"requiresBillingAgreement":false,"merchantId":"L873BZSC9NMQS","sdkUrl":"https://www.paypal.com/sdk/js?components=buttons\u0026commit=false\u0026currency=USD\u0026locale=en_US\u0026client-id=AbasDhzlU0HbpiStJiN1KRJ_cNJJ7xYBip7JJoMO0GQpLi8ePNgdbLXkC7_KMeyTg8tnAKW4WKrh9qmf\u0026merchant-id=L873BZSC9NMQS\u0026intent=authorize"}}]" access-token="c0f52a66b386e9fa5c0ab4c2febc737c" buyer-country="US" buyer-locale="en" buyer-currency="USD" shop-id="73758048501" cart-id="19d86c9c79ba615de16c57665305e096" enabled-flags="["d6d12da0","32a68cd0","a1c7ccbe","ce346acf","c0874428"]" > <div class="wallet-button-wrapper"> <ul class='wallet-cart-grid wallet-cart-grid--skeleton' role="list" data-shopify-buttoncontainer="true"> <li data-testid='grid-cell' class='wallet-cart-button-container'><div class='wallet-cart-button wallet-cart-button__skeleton' role='button' disabled aria-hidden='true'> </div></li><li data-testid='grid-cell' class='wallet-cart-button-container'><div class='wallet-cart-button wallet-cart-button__skeleton' role='button' disabled aria-hidden='true'> </div></li><li data-testid='grid-cell' class='wallet-cart-button-container'><div class='wallet-cart-button wallet-cart-button__skeleton' role='button' disabled aria-hidden='true'> </div></li> </ul> </div> </shopify-accelerated-checkout-cart> <small id="shopify-buyer-consent" class="hidden" aria-hidden="true" data-consent-type="subscription"> One or more of the items in your cart is a recurring or deferred purchase. By continuing, I agree to the <span id="shopify-subscription-policy-button">cancellation policy</span> and authorize you to charge my payment method at the prices, frequency and dates listed on this page until my order is fulfilled or I cancel, if permitted. </small> </div>
Stay in the know
Subscribe to our newsletter and stay updated on latest offers, discounts and events near you.
For MAP (Minimum Advertised Price) violations and Intellectual Property (IP) or Trademark concerns, please contact:
support@ergodebooks.com
⚠️ California Proposition 65 Warning: Some products sold on this website may expose you to chemicals known to the State of California to cause cancer, birth defects, or other reproductive harm. For more information, visit www.P65Warnings.ca.gov.