{"product_id":"integrating-out-the-dirac-sea-a-no-sea-effective-theory-approach-von-felix-karbstein","title":"Integrating out the Dirac Sea","description":"\u003cp\u003eWe introduce a new method for dealing with fermionic quantum field theories amenable to a mean-field-type approximation. In this book we focus on the relativistic Hartree approximation. Our aim is to integrate out the Dirac sea and derive a \"no-sea effective theory\" with positive energy single particle states only. As the derivation of the no-sea effective theory involves only standard Feynman diagrams, our approach is quite general and not restricted to particular space-time dimensions. We develop and illustrate the approach in the \"large N\" limit of the Gross-Neveu model family in 1+1 dimensions, which serves as an ideal testing ground for our no-sea effective theory approach. The chiral Gross-Neveu model, also referred to as Nambu-Jona-Lasinio model, turns out to be of particular interest. In this case, we explicitly derive a consistent effective theory featuring both elementary \"Pi meson\" fields and (positive energy) \"quark\" fields, starting from a purely fermionic quantum field theory. In the second part of this book, we apply our approach to the Walecka model in 1+1 and 3+1 dimensions.\u003c\/p\u003e\u003cdiv class=\"aw-variant-hidden-subtitle-div\" id=\"aw-variant-subtitle-9783838110103\"\u003e\u003ch3\u003eA no-sea effective theory approach\u003c\/h3\u003e\u003c\/div\u003e","brand":"Libri","offers":[{"title":"Softcover - 9783838110103","offer_id":39456564117597,"sku":"9783838110103","price":53.9,"currency_code":"EUR","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0940\/0622\/files\/1b840c26-99cd-4937-bdc9-7a961a6ea1b0.jpg?v=1776314950","url":"https:\/\/shop.autorenwelt.de\/products\/integrating-out-the-dirac-sea-a-no-sea-effective-theory-approach-von-felix-karbstein","provider":"Autorenwelt Shop","version":"1.0","type":"link"}