Let lsi1" class="mathmlsrc">lass="formulatext stixSupport mathImg" data-mathURL="/science?_ob=MathURL&_method=retrieve&_eid=1-s2.0-S0167715216300608&_mathId=si1.gif&_user=111111111&_pii=S0167715216300608&_rdoc=1&_issn=01677152&md5=aa82a7dded6f8c9ec89e2a3dba7c8cbb" title="Click to view the MathML source">πlass="mathContainer hidden">lass="mathCode"> be a positive continuous target density on lsi2" class="mathmlsrc">lass="formulatext stixSupport mathImg" data-mathURL="/science?_ob=MathURL&_method=retrieve&_eid=1-s2.0-S0167715216300608&_mathId=si2.gif&_user=111111111&_pii=S0167715216300608&_rdoc=1&_issn=01677152&md5=5909e71ebace475fd405fd2be08510f9" title="Click to view the MathML source">Rlass="mathContainer hidden">lass="mathCode">. Let lsi3" class="mathmlsrc">lass="formulatext stixSupport mathImg" data-mathURL="/science?_ob=MathURL&_method=retrieve&_eid=1-s2.0-S0167715216300608&_mathId=si3.gif&_user=111111111&_pii=S0167715216300608&_rdoc=1&_issn=01677152&md5=26bcdced0c26f13df9dcede512eb6345" title="Click to view the MathML source">Plass="mathContainer hidden">lass="mathCode"> be the Metropolis–Hastings operator on the Lebesgue space lsi4" class="mathmlsrc">lass="formulatext stixSupport mathImg" data-mathURL="/science?_ob=MathURL&_method=retrieve&_eid=1-s2.0-S0167715216300608&_mathId=si4.gif&_user=111111111&_pii=S0167715216300608&_rdoc=1&_issn=01677152&md5=d3c11f1dbd054d00b4a0ffe238b0ef9a" title="Click to view the MathML source">L2(π)lass="mathContainer hidden">lass="mathCode"> corresponding to a proposal Markov kernel lsi5" class="mathmlsrc">lass="formulatext stixSupport mathImg" data-mathURL="/science?_ob=MathURL&_method=retrieve&_eid=1-s2.0-S0167715216300608&_mathId=si5.gif&_user=111111111&_pii=S0167715216300608&_rdoc=1&_issn=01677152&md5=407bc19e3e1bc6c27ea24c7aa986b8ac" title="Click to view the MathML source">Qlass="mathContainer hidden">lass="mathCode"> on lsi2" class="mathmlsrc">lass="formulatext stixSupport mathImg" data-mathURL="/science?_ob=MathURL&_method=retrieve&_eid=1-s2.0-S0167715216300608&_mathId=si2.gif&_user=111111111&_pii=S0167715216300608&_rdoc=1&_issn=01677152&md5=5909e71ebace475fd405fd2be08510f9" title="Click to view the MathML source">Rlass="mathContainer hidden">lass="mathCode">. When using the quasi-compactness method to estimate the spectral gap of lsi3" class="mathmlsrc">lass="formulatext stixSupport mathImg" data-mathURL="/science?_ob=MathURL&_method=retrieve&_eid=1-s2.0-S0167715216300608&_mathId=si3.gif&_user=111111111&_pii=S0167715216300608&_rdoc=1&_issn=01677152&md5=26bcdced0c26f13df9dcede512eb6345" title="Click to view the MathML source">Plass="mathContainer hidden">lass="mathCode">, a mandatory first step is to obtain an accurate bound of the essential spectral radius lsi8" class="mathmlsrc">lass="formulatext stixSupport mathImg" data-mathURL="/science?_ob=MathURL&_method=retrieve&_eid=1-s2.0-S0167715216300608&_mathId=si8.gif&_user=111111111&_pii=S0167715216300608&_rdoc=1&_issn=01677152&md5=4653b84015949fd6e102634393fd2bc4" title="Click to view the MathML source">ress(P)lass="mathContainer hidden">lass="mathCode"> of lsi3" class="mathmlsrc">lass="formulatext stixSupport mathImg" data-mathURL="/science?_ob=MathURL&_method=retrieve&_eid=1-s2.0-S0167715216300608&_mathId=si3.gif&_user=111111111&_pii=S0167715216300608&_rdoc=1&_issn=01677152&md5=26bcdced0c26f13df9dcede512eb6345" title="Click to view the MathML source">Plass="mathContainer hidden">lass="mathCode">. In this paper a computable bound of lsi8" class="mathmlsrc">lass="formulatext stixSupport mathImg" data-mathURL="/science?_ob=MathURL&_method=retrieve&_eid=1-s2.0-S0167715216300608&_mathId=si8.gif&_user=111111111&_pii=S0167715216300608&_rdoc=1&_issn=01677152&md5=4653b84015949fd6e102634393fd2bc4" title="Click to view the MathML source">ress(P)lass="mathContainer hidden">lass="mathCode"> is obtained under the following assumption on the proposal kernel: lsi5" class="mathmlsrc">lass="formulatext stixSupport mathImg" data-mathURL="/science?_ob=MathURL&_method=retrieve&_eid=1-s2.0-S0167715216300608&_mathId=si5.gif&_user=111111111&_pii=S0167715216300608&_rdoc=1&_issn=01677152&md5=407bc19e3e1bc6c27ea24c7aa986b8ac" title="Click to view the MathML source">Qlass="mathContainer hidden">lass="mathCode"> has a bounded continuous density lsi12" class="mathmlsrc">lass="formulatext stixSupport mathImg" data-mathURL="/science?_ob=MathURL&_method=retrieve&_eid=1-s2.0-S0167715216300608&_mathId=si12.gif&_user=111111111&_pii=S0167715216300608&_rdoc=1&_issn=01677152&md5=1ad746e4510b4ed9663561b4983955ac" title="Click to view the MathML source">q(x,y)lass="mathContainer hidden">lass="mathCode"> on lsi13" class="mathmlsrc">lass="formulatext stixSupport mathImg" data-mathURL="/science?_ob=MathURL&_method=retrieve&_eid=1-s2.0-S0167715216300608&_mathId=si13.gif&_user=111111111&_pii=S0167715216300608&_rdoc=1&_issn=01677152&md5=af78ac92b65d96e423994cb4eec73d03" title="Click to view the MathML source">R2lass="mathContainer hidden">lass="mathCode"> satisfying the following finite range assumption : lsi14" class="mathmlsrc">le="View the MathML source" class="mathImg" data-mathURL="/science?_ob=MathURL&_method=retrieve&_eid=1-s2.0-S0167715216300608&_mathId=si14.gif&_user=111111111&_pii=S0167715216300608&_rdoc=1&_issn=01677152&md5=433ef4d8cd28d1518ebab0d066dad755">lass="imgLazyJSB inlineImage" height="15" width="180" alt="View the MathML source" style="margin-top: -5px; vertical-align: middle" title="View the MathML source" src="/sd/grey_pxl.gif" data-inlimgeid="1-s2.0-S0167715216300608-si14.gif">lass="mathContainer hidden">lass="mathCode"> (for some lsi15" class="mathmlsrc">lass="formulatext stixSupport mathImg" data-mathURL="/science?_ob=MathURL&_method=retrieve&_eid=1-s2.0-S0167715216300608&_mathId=si15.gif&_user=111111111&_pii=S0167715216300608&_rdoc=1&_issn=01677152&md5=e702ccb5bb0e1920be9e2692589fa11b" title="Click to view the MathML source">s>0lass="mathContainer hidden">lass="mathCode">). This result is illustrated with Random Walk Metropolis–Hastings kernels.